diff --git a/src/main/java/seedu/address/logic/commands/EditCommand.java b/src/main/java/seedu/address/logic/commands/EditCommand.java
index 4b581c7331e..c5c985e1387 100644
--- a/src/main/java/seedu/address/logic/commands/EditCommand.java
+++ b/src/main/java/seedu/address/logic/commands/EditCommand.java
@@ -21,6 +21,7 @@
 import seedu.address.logic.Messages;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -100,8 +101,9 @@ private static Person createEditedPerson(Person personToEdit, EditPersonDescript
         Email updatedEmail = editPersonDescriptor.getEmail().orElse(personToEdit.getEmail());
         Address updatedAddress = editPersonDescriptor.getAddress().orElse(personToEdit.getAddress());
         Set<Tag> updatedTags = editPersonDescriptor.getTags().orElse(personToEdit.getTags());
+        Set<Grade> updatedGrades = editPersonDescriptor.getGrades().orElse(personToEdit.getGrades());
 
-        return new Person(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedTags);
+        return new Person(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedTags, updatedGrades);
     }
 
     @Override
@@ -139,6 +141,8 @@ public static class EditPersonDescriptor {
         private Address address;
         private Set<Tag> tags;
 
+        private Set<Grade> grades;
+
         public EditPersonDescriptor() {}
 
         /**
@@ -151,13 +155,14 @@ public EditPersonDescriptor(EditPersonDescriptor toCopy) {
             setEmail(toCopy.email);
             setAddress(toCopy.address);
             setTags(toCopy.tags);
+            setGrades(toCopy.grades);
         }
 
         /**
          * Returns true if at least one field is edited.
          */
         public boolean isAnyFieldEdited() {
-            return CollectionUtil.isAnyNonNull(name, phone, email, address, tags);
+            return CollectionUtil.isAnyNonNull(name, phone, email, address, tags, grades);
         }
 
         public void setName(Name name) {
@@ -209,6 +214,23 @@ public Optional<Set<Tag>> getTags() {
             return (tags != null) ? Optional.of(Collections.unmodifiableSet(tags)) : Optional.empty();
         }
 
+        /**
+         * Sets {@code grades} to this object's {@code grades}.
+         * A defensive copy of {@code grades} is used internally.
+         */
+        public void setGrades(Set<Grade> grades) {
+            this.grades = (grades != null) ? new HashSet<>(grades) : null;
+        }
+
+        /**
+         * Returns an unmodifiable grades set, which throws {@code UnsupportedOperationException}
+         * if modification is attempted.
+         * Returns {@code Optional#empty()} if {@code grades} is null.
+         */
+        public Optional<Set<Grade>> getGrades() {
+            return (grades != null) ? Optional.of(Collections.unmodifiableSet(grades)) : Optional.empty();
+        }
+
         @Override
         public boolean equals(Object other) {
             if (other == this) {
@@ -236,6 +258,7 @@ public String toString() {
                     .add("email", email)
                     .add("address", address)
                     .add("tags", tags)
+                    .add("grades", grades)
                     .toString();
         }
     }
diff --git a/src/main/java/seedu/address/logic/parser/AddCommandParser.java b/src/main/java/seedu/address/logic/parser/AddCommandParser.java
index 4ff1a97ed77..b33b06993ee 100644
--- a/src/main/java/seedu/address/logic/parser/AddCommandParser.java
+++ b/src/main/java/seedu/address/logic/parser/AddCommandParser.java
@@ -3,6 +3,7 @@
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_GRADE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_TAG;
@@ -12,6 +13,7 @@
 
 import seedu.address.logic.commands.AddCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -31,7 +33,8 @@ public class AddCommandParser implements Parser<AddCommand> {
      */
     public AddCommand parse(String args) throws ParseException {
         ArgumentMultimap argMultimap =
-                ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_ADDRESS, PREFIX_TAG);
+                ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE,
+                        PREFIX_EMAIL, PREFIX_ADDRESS, PREFIX_TAG, PREFIX_GRADE);
 
         if (!arePrefixesPresent(argMultimap, PREFIX_NAME, PREFIX_ADDRESS, PREFIX_PHONE, PREFIX_EMAIL)
                 || !argMultimap.getPreamble().isEmpty()) {
@@ -44,8 +47,9 @@ public AddCommand parse(String args) throws ParseException {
         Email email = ParserUtil.parseEmail(argMultimap.getValue(PREFIX_EMAIL).get());
         Address address = ParserUtil.parseAddress(argMultimap.getValue(PREFIX_ADDRESS).get());
         Set<Tag> tagList = ParserUtil.parseTags(argMultimap.getAllValues(PREFIX_TAG));
+        Set<Grade> gradeList = ParserUtil.parseGrades(argMultimap.getAllValues(PREFIX_GRADE));
 
-        Person person = new Person(name, phone, email, address, tagList);
+        Person person = new Person(name, phone, email, address, tagList, gradeList);
 
         return new AddCommand(person);
     }
diff --git a/src/main/java/seedu/address/logic/parser/CliSyntax.java b/src/main/java/seedu/address/logic/parser/CliSyntax.java
index 75b1a9bf119..949cf0b9f55 100644
--- a/src/main/java/seedu/address/logic/parser/CliSyntax.java
+++ b/src/main/java/seedu/address/logic/parser/CliSyntax.java
@@ -11,5 +11,6 @@ public class CliSyntax {
     public static final Prefix PREFIX_EMAIL = new Prefix("e/");
     public static final Prefix PREFIX_ADDRESS = new Prefix("a/");
     public static final Prefix PREFIX_TAG = new Prefix("t/");
+    public static final Prefix PREFIX_GRADE = new Prefix("g/");
 
 }
diff --git a/src/main/java/seedu/address/logic/parser/ParserUtil.java b/src/main/java/seedu/address/logic/parser/ParserUtil.java
index b117acb9c55..63ee2da7088 100644
--- a/src/main/java/seedu/address/logic/parser/ParserUtil.java
+++ b/src/main/java/seedu/address/logic/parser/ParserUtil.java
@@ -9,6 +9,7 @@
 import seedu.address.commons.core.index.Index;
 import seedu.address.commons.util.StringUtil;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -121,4 +122,31 @@ public static Set<Tag> parseTags(Collection<String> tags) throws ParseException
         }
         return tagSet;
     }
+
+    /**
+     * Parses a {@code String grade} into a {@code grade}.
+     * Leading and trailing whitespaces will be trimmed.
+     *
+     * @throws ParseException if the given {@code grade} is invalid.
+     */
+    public static Grade parseGrade(String grade) throws ParseException {
+        requireNonNull(grade);
+        String trimmedGrade = grade.trim();
+        if (!Grade.isValidGrade(trimmedGrade)) {
+            throw new ParseException(Tag.MESSAGE_CONSTRAINTS);
+        }
+        return new Grade(trimmedGrade);
+    }
+
+    /**
+     * Parses {@code Collection<String> grades} into a {@code Set<Grade>}.
+     */
+    public static Set<Grade> parseGrades(Collection<String> grades) throws ParseException {
+        requireNonNull(grades);
+        final Set<Grade> gradeSet = new HashSet<>();
+        for (String grade : grades) {
+            gradeSet.add(parseGrade(grade));
+        }
+        return gradeSet;
+    }
 }
diff --git a/src/main/java/seedu/address/model/grade/Grade.java b/src/main/java/seedu/address/model/grade/Grade.java
new file mode 100644
index 00000000000..071f16940d3
--- /dev/null
+++ b/src/main/java/seedu/address/model/grade/Grade.java
@@ -0,0 +1,82 @@
+package seedu.address.model.grade;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.commons.util.AppUtil.checkArgument;
+
+import java.util.Objects;
+/**
+ * Represents a Person's Grade in the address book.
+ * Guarantees: immutable; is valid as declared in {@link #isValidGrade(String)}
+ */
+public class Grade {
+
+    public static final String MESSAGE_CONSTRAINTS = "Grades should be of the format Test: Grade "
+            + "and adhere to the following constraints:\n"
+            + "1. The Test name should not be empty"
+            + "2. This is followed by a ': ' and then a grade. \n"
+            + "The grade must:\n"
+            + "    - represent the percentage gotten in the test rounded to the nearest whole number\n"
+            + "    - be between [0, 100]\n";
+
+    /*
+     * The first character of the test name must not be a whitespace,
+     * otherwise " " (a blank string) becomes a valid input.
+     * Grade should be an integer ranging from 0-100, representing the percentage.
+     */
+    public static final String TEST_NAME_VALIDATION_REGEX = ".+?";
+    public static final String GRADE_VALIDATION_REGEX = "(100|[1-9]?[0-9])$";
+
+    public static final String VALIDATION_REGEX = TEST_NAME_VALIDATION_REGEX + ":\\s*" + GRADE_VALIDATION_REGEX;
+
+    public final String testAndGrade;
+    public final String testName;
+    public final String grade;
+
+    /**
+     * Constructs an {@code Grade}.
+     *
+     * @param testAndGrade A valid testAndGrade.
+     */
+    public Grade(String testAndGrade) {
+        requireNonNull(testAndGrade);
+        checkArgument(isValidGrade(testAndGrade.trim()), MESSAGE_CONSTRAINTS);
+        String[] parts = testAndGrade.split(":", 2);
+        this.testName = parts[0].trim();
+        this.grade = parts[1].trim();
+        this.testAndGrade = testAndGrade;
+    }
+
+    /**
+     * Returns true if a given string is a valid grade.
+     */
+    public static boolean isValidGrade(String test) {
+        return test.matches(VALIDATION_REGEX);
+    }
+
+
+    @Override
+    public String toString() {
+        return testName + ": " + grade;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof Grade)) {
+            return false;
+        }
+
+        Grade otherGrade = (Grade) other;
+        return testName.equals(otherGrade.testName) && grade.equals(otherGrade.grade);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(testName, grade);
+    }
+
+}
diff --git a/src/main/java/seedu/address/model/person/Person.java b/src/main/java/seedu/address/model/person/Person.java
index abe8c46b535..75df0c467c7 100644
--- a/src/main/java/seedu/address/model/person/Person.java
+++ b/src/main/java/seedu/address/model/person/Person.java
@@ -8,6 +8,7 @@
 import java.util.Set;
 
 import seedu.address.commons.util.ToStringBuilder;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.tag.Tag;
 
 /**
@@ -25,16 +26,19 @@ public class Person {
     private final Address address;
     private final Set<Tag> tags = new HashSet<>();
 
+    private final Set<Grade> grades = new HashSet<>();
+
     /**
      * Every field must be present and not null.
      */
-    public Person(Name name, Phone phone, Email email, Address address, Set<Tag> tags) {
-        requireAllNonNull(name, phone, email, address, tags);
+    public Person(Name name, Phone phone, Email email, Address address, Set<Tag> tags, Set<Grade> grades) {
+        requireAllNonNull(name, phone, email, address, tags, grades);
         this.name = name;
         this.phone = phone;
         this.email = email;
         this.address = address;
         this.tags.addAll(tags);
+        this.grades.addAll(grades);
     }
 
     public Name getName() {
@@ -61,6 +65,14 @@ public Set<Tag> getTags() {
         return Collections.unmodifiableSet(tags);
     }
 
+    /**
+     * Returns an immutable grade set, which throws {@code UnsupportedOperationException}
+     * if modification is attempted.
+     */
+    public Set<Grade> getGrades() {
+        return Collections.unmodifiableSet(grades);
+    }
+
     /**
      * Returns true if both persons have the same name.
      * This defines a weaker notion of equality between two persons.
@@ -94,13 +106,14 @@ public boolean equals(Object other) {
                 && phone.equals(otherPerson.phone)
                 && email.equals(otherPerson.email)
                 && address.equals(otherPerson.address)
-                && tags.equals(otherPerson.tags);
+                && tags.equals(otherPerson.tags)
+                && grades.equals(otherPerson.grades);
     }
 
     @Override
     public int hashCode() {
         // use this method for custom fields hashing instead of implementing your own
-        return Objects.hash(name, phone, email, address, tags);
+        return Objects.hash(name, phone, email, address, tags, grades);
     }
 
     @Override
@@ -111,6 +124,7 @@ public String toString() {
                 .add("email", email)
                 .add("address", address)
                 .add("tags", tags)
+                .add("grades", grades)
                 .toString();
     }
 
diff --git a/src/main/java/seedu/address/model/util/SampleDataUtil.java b/src/main/java/seedu/address/model/util/SampleDataUtil.java
index 1806da4facf..0bfc8fdaa8e 100644
--- a/src/main/java/seedu/address/model/util/SampleDataUtil.java
+++ b/src/main/java/seedu/address/model/util/SampleDataUtil.java
@@ -6,6 +6,7 @@
 
 import seedu.address.model.AddressBook;
 import seedu.address.model.ReadOnlyAddressBook;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -21,22 +22,22 @@ public static Person[] getSamplePersons() {
         return new Person[] {
             new Person(new Name("Alex Yeoh"), new Phone("87438807"), new Email("alexyeoh@example.com"),
                 new Address("Blk 30 Geylang Street 29, #06-40"),
-                getTagSet("friends")),
+                getTagSet("friends"), getGradeSet("ca1: 90")),
             new Person(new Name("Bernice Yu"), new Phone("99272758"), new Email("berniceyu@example.com"),
                 new Address("Blk 30 Lorong 3 Serangoon Gardens, #07-18"),
-                getTagSet("colleagues", "friends")),
+                getTagSet("colleagues", "friends"), getGradeSet("ca1: 50", "ca2: 80")),
             new Person(new Name("Charlotte Oliveiro"), new Phone("93210283"), new Email("charlotte@example.com"),
                 new Address("Blk 11 Ang Mo Kio Street 74, #11-04"),
-                getTagSet("neighbours")),
+                getTagSet("neighbours"), getGradeSet("eoy: 70")),
             new Person(new Name("David Li"), new Phone("91031282"), new Email("lidavid@example.com"),
                 new Address("Blk 436 Serangoon Gardens Street 26, #16-43"),
-                getTagSet("family")),
+                getTagSet("family"), getGradeSet("midterms: 0")),
             new Person(new Name("Irfan Ibrahim"), new Phone("92492021"), new Email("irfan@example.com"),
                 new Address("Blk 47 Tampines Street 20, #17-35"),
-                getTagSet("classmates")),
+                getTagSet("classmates"), getGradeSet("finals: 100")),
             new Person(new Name("Roy Balakrishnan"), new Phone("92624417"), new Email("royb@example.com"),
                 new Address("Blk 45 Aljunied Street 85, #11-31"),
-                getTagSet("colleagues"))
+                getTagSet("colleagues"), getGradeSet("ca2: 39"))
         };
     }
 
@@ -57,4 +58,13 @@ public static Set<Tag> getTagSet(String... strings) {
                 .collect(Collectors.toSet());
     }
 
+    /**
+     * Returns a grade set containing the list of strings given.
+     */
+    public static Set<Grade> getGradeSet(String... strings) {
+        return Arrays.stream(strings)
+                .map(Grade::new)
+                .collect(Collectors.toSet());
+    }
+
 }
diff --git a/src/main/java/seedu/address/storage/JsonAdaptedGrade.java b/src/main/java/seedu/address/storage/JsonAdaptedGrade.java
new file mode 100644
index 00000000000..e909e5e43d4
--- /dev/null
+++ b/src/main/java/seedu/address/storage/JsonAdaptedGrade.java
@@ -0,0 +1,48 @@
+package seedu.address.storage;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+
+import seedu.address.commons.exceptions.IllegalValueException;
+import seedu.address.model.grade.Grade;
+
+/**
+ * Jackson-friendly version of {@link Grade}.
+ */
+class JsonAdaptedGrade {
+
+    private final String grade;
+
+    /**
+     * Constructs a {@code JsonAdaptedGrade} with the given {@code grade}.
+     */
+    @JsonCreator
+    public JsonAdaptedGrade(String grade) {
+        this.grade = grade;
+    }
+
+    /**
+     * Converts a given {@code Grade} into this class for Jackson use.
+     */
+    public JsonAdaptedGrade(Grade source) {
+        grade = source.testAndGrade;
+    }
+
+    @JsonValue
+    public String getGrade() {
+        return grade;
+    }
+
+    /**
+     * Converts this Jackson-friendly adapted tag object into the model's {@code Grade} object.
+     *
+     * @throws IllegalValueException if there were any data constraints violated in the adapted grade.
+     */
+    public Grade toModelType() throws IllegalValueException {
+        if (!Grade.isValidGrade(grade)) {
+            throw new IllegalValueException(Grade.MESSAGE_CONSTRAINTS);
+        }
+        return new Grade(grade);
+    }
+
+}
diff --git a/src/main/java/seedu/address/storage/JsonAdaptedPerson.java b/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
index bd1ca0f56c8..fb76754bc20 100644
--- a/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
+++ b/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
@@ -10,6 +10,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import seedu.address.commons.exceptions.IllegalValueException;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -30,13 +31,15 @@ class JsonAdaptedPerson {
     private final String address;
     private final List<JsonAdaptedTag> tags = new ArrayList<>();
 
+    private final List<JsonAdaptedGrade> grades = new ArrayList<>();
+
     /**
      * Constructs a {@code JsonAdaptedPerson} with the given person details.
      */
     @JsonCreator
     public JsonAdaptedPerson(@JsonProperty("name") String name, @JsonProperty("phone") String phone,
             @JsonProperty("email") String email, @JsonProperty("address") String address,
-            @JsonProperty("tags") List<JsonAdaptedTag> tags) {
+            @JsonProperty("tags") List<JsonAdaptedTag> tags, @JsonProperty("grades") List<JsonAdaptedGrade> grades) {
         this.name = name;
         this.phone = phone;
         this.email = email;
@@ -44,6 +47,9 @@ public JsonAdaptedPerson(@JsonProperty("name") String name, @JsonProperty("phone
         if (tags != null) {
             this.tags.addAll(tags);
         }
+        if (grades != null) {
+            this.grades.addAll(grades);
+        }
     }
 
     /**
@@ -57,6 +63,9 @@ public JsonAdaptedPerson(Person source) {
         tags.addAll(source.getTags().stream()
                 .map(JsonAdaptedTag::new)
                 .collect(Collectors.toList()));
+        grades.addAll(source.getGrades().stream()
+                .map(JsonAdaptedGrade::new)
+                .collect(Collectors.toList()));
     }
 
     /**
@@ -70,6 +79,11 @@ public Person toModelType() throws IllegalValueException {
             personTags.add(tag.toModelType());
         }
 
+        final List<Grade> personGrades = new ArrayList<>();
+        for (JsonAdaptedGrade grade : grades) {
+            personGrades.add(grade.toModelType());
+        }
+
         if (name == null) {
             throw new IllegalValueException(String.format(MISSING_FIELD_MESSAGE_FORMAT, Name.class.getSimpleName()));
         }
@@ -103,7 +117,8 @@ public Person toModelType() throws IllegalValueException {
         final Address modelAddress = new Address(address);
 
         final Set<Tag> modelTags = new HashSet<>(personTags);
-        return new Person(modelName, modelPhone, modelEmail, modelAddress, modelTags);
+        final Set<Grade> modelGrades = new HashSet<>(personGrades);
+        return new Person(modelName, modelPhone, modelEmail, modelAddress, modelTags, modelGrades);
     }
 
 }
diff --git a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
index a7427fe7aa2..056a393909c 100644
--- a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
@@ -4,7 +4,8 @@
     "phone": "94351253",
     "email": "alice@example.com",
     "address": "123, Jurong West Ave 6, #08-111",
-    "tags": [ "friends" ]
+    "tags": [ "friends" ],
+    "grades": [ "ca1: 50"]
   }, {
     "name": "Alice Pauline",
     "phone": "94351253",
diff --git a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
index 72262099d35..4a512662214 100644
--- a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
@@ -5,42 +5,49 @@
     "phone" : "94351253",
     "email" : "alice@example.com",
     "address" : "123, Jurong West Ave 6, #08-111",
-    "tags" : [ "friends" ]
+    "tags" : [ "friends" ],
+    "grades": [ "ca1: 20"]
   }, {
     "name" : "Benson Meier",
     "phone" : "98765432",
     "email" : "johnd@example.com",
     "address" : "311, Clementi Ave 2, #02-25",
-    "tags" : [ "owesMoney", "friends" ]
+    "tags" : [ "owesMoney", "friends" ],
+    "grades": [ "ca1: 90"]
   }, {
     "name" : "Carl Kurz",
     "phone" : "95352563",
     "email" : "heinz@example.com",
     "address" : "wall street",
-    "tags" : [ ]
+    "tags" : [ ],
+    "grades": [ ]
   }, {
     "name" : "Daniel Meier",
     "phone" : "87652533",
     "email" : "cornelia@example.com",
     "address" : "10th street",
-    "tags" : [ "friends" ]
+    "tags" : [ "friends" ],
+    "grades": [ ]
   }, {
     "name" : "Elle Meyer",
     "phone" : "9482224",
     "email" : "werner@example.com",
     "address" : "michegan ave",
-    "tags" : [ ]
+    "tags" : [ ],
+    "grades": [ ]
   }, {
     "name" : "Fiona Kunz",
     "phone" : "9482427",
     "email" : "lydia@example.com",
     "address" : "little tokyo",
-    "tags" : [ ]
+    "tags" : [ ],
+    "grades": [ ]
   }, {
     "name" : "George Best",
     "phone" : "9482442",
     "email" : "anna@example.com",
     "address" : "4th street",
-    "tags" : [ ]
+    "tags" : [ ],
+    "grades": [ ]
   } ]
 }
diff --git a/src/test/java/seedu/address/logic/LogicManagerTest.java b/src/test/java/seedu/address/logic/LogicManagerTest.java
index baf8ce336a2..9936a118e3a 100644
--- a/src/test/java/seedu/address/logic/LogicManagerTest.java
+++ b/src/test/java/seedu/address/logic/LogicManagerTest.java
@@ -167,7 +167,7 @@ public void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath)
         // Triggers the saveAddressBook method by executing an add command
         String addCommand = AddCommand.COMMAND_WORD + NAME_DESC_AMY + PHONE_DESC_AMY
                 + EMAIL_DESC_AMY + ADDRESS_DESC_AMY;
-        Person expectedPerson = new PersonBuilder(AMY).withTags().build();
+        Person expectedPerson = new PersonBuilder(AMY).withTags().withGrades().build();
         ModelManager expectedModel = new ModelManager();
         expectedModel.addPerson(expectedPerson);
         assertCommandFailure(addCommand, CommandException.class, expectedMessage, expectedModel);
diff --git a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
index 643a1d08069..48a65177600 100644
--- a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
+++ b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
@@ -36,6 +36,7 @@ public class CommandTestUtil {
     public static final String VALID_ADDRESS_BOB = "Block 123, Bobby Street 3";
     public static final String VALID_TAG_HUSBAND = "husband";
     public static final String VALID_TAG_FRIEND = "friend";
+    public static final String VALID_GRADE_CA1_100 = "ca1: 100";
 
     public static final String NAME_DESC_AMY = " " + PREFIX_NAME + VALID_NAME_AMY;
     public static final String NAME_DESC_BOB = " " + PREFIX_NAME + VALID_NAME_BOB;
diff --git a/src/test/java/seedu/address/logic/commands/EditPersonDescriptorTest.java b/src/test/java/seedu/address/logic/commands/EditPersonDescriptorTest.java
index b17c1f3d5c2..f101a3ee90f 100644
--- a/src/test/java/seedu/address/logic/commands/EditPersonDescriptorTest.java
+++ b/src/test/java/seedu/address/logic/commands/EditPersonDescriptorTest.java
@@ -65,7 +65,8 @@ public void toStringMethod() {
                 + editPersonDescriptor.getPhone().orElse(null) + ", email="
                 + editPersonDescriptor.getEmail().orElse(null) + ", address="
                 + editPersonDescriptor.getAddress().orElse(null) + ", tags="
-                + editPersonDescriptor.getTags().orElse(null) + "}";
+                + editPersonDescriptor.getTags().orElse(null) + ", grades="
+                + editPersonDescriptor.getGrades().orElse(null) + "}";
         assertEquals(expected, editPersonDescriptor.toString());
     }
 }
diff --git a/src/test/java/seedu/address/logic/parser/AddCommandParserTest.java b/src/test/java/seedu/address/logic/parser/AddCommandParserTest.java
index 5bc11d3cdaa..f507c9cf631 100644
--- a/src/test/java/seedu/address/logic/parser/AddCommandParserTest.java
+++ b/src/test/java/seedu/address/logic/parser/AddCommandParserTest.java
@@ -132,7 +132,7 @@ public void parse_repeatedNonTagValue_failure() {
     @Test
     public void parse_optionalFieldsMissing_success() {
         // zero tags
-        Person expectedPerson = new PersonBuilder(AMY).withTags().build();
+        Person expectedPerson = new PersonBuilder(AMY).withTags().withGrades().build();
         assertParseSuccess(parser, NAME_DESC_AMY + PHONE_DESC_AMY + EMAIL_DESC_AMY + ADDRESS_DESC_AMY,
                 new AddCommand(expectedPerson));
     }
diff --git a/src/test/java/seedu/address/model/person/PersonTest.java b/src/test/java/seedu/address/model/person/PersonTest.java
index 31a10d156c9..58bf4494f70 100644
--- a/src/test/java/seedu/address/model/person/PersonTest.java
+++ b/src/test/java/seedu/address/model/person/PersonTest.java
@@ -93,7 +93,8 @@ public void equals() {
     @Test
     public void toStringMethod() {
         String expected = Person.class.getCanonicalName() + "{name=" + ALICE.getName() + ", phone=" + ALICE.getPhone()
-                + ", email=" + ALICE.getEmail() + ", address=" + ALICE.getAddress() + ", tags=" + ALICE.getTags() + "}";
+                + ", email=" + ALICE.getEmail() + ", address=" + ALICE.getAddress() + ", tags=" + ALICE.getTags()
+                + ", grades=" + ALICE.getGrades() + "}";
         assertEquals(expected, ALICE.toString());
     }
 }
diff --git a/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java b/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
index 83b11331cdb..e5e41cb3934 100644
--- a/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
+++ b/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
@@ -23,6 +23,7 @@ public class JsonAdaptedPersonTest {
     private static final String INVALID_ADDRESS = " ";
     private static final String INVALID_EMAIL = "example.com";
     private static final String INVALID_TAG = "#friend";
+    private static final String INVALID_GRADE = "hello";
 
     private static final String VALID_NAME = BENSON.getName().toString();
     private static final String VALID_PHONE = BENSON.getPhone().toString();
@@ -32,23 +33,30 @@ public class JsonAdaptedPersonTest {
             .map(JsonAdaptedTag::new)
             .collect(Collectors.toList());
 
+    private static final List<JsonAdaptedGrade> VALID_GRADES = BENSON.getGrades().stream()
+            .map(JsonAdaptedGrade::new)
+            .collect(Collectors.toList());
+
     @Test
     public void toModelType_validPersonDetails_returnsPerson() throws Exception {
         JsonAdaptedPerson person = new JsonAdaptedPerson(BENSON);
+        System.out.println(person.toModelType());
+        System.out.println(BENSON);
         assertEquals(BENSON, person.toModelType());
     }
 
     @Test
     public void toModelType_invalidName_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS);
+                new JsonAdaptedPerson(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = Name.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullName_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(null, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(null, VALID_PHONE, VALID_EMAIL,
+                VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Name.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -56,14 +64,15 @@ public void toModelType_nullName_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidPhone_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = Phone.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullPhone_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, null, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, null, VALID_EMAIL,
+                VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Phone.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -71,14 +80,15 @@ public void toModelType_nullPhone_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidEmail_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_ADDRESS, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = Email.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullEmail_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, null, VALID_ADDRESS, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, null,
+                VALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Email.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -86,14 +96,15 @@ public void toModelType_nullEmail_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidAddress_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_ADDRESS, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_ADDRESS, VALID_TAGS, VALID_GRADES);
         String expectedMessage = Address.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullAddress_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, null, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL,
+                null, VALID_TAGS, VALID_GRADES);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Address.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -103,7 +114,16 @@ public void toModelType_invalidTags_throwsIllegalValueException() {
         List<JsonAdaptedTag> invalidTags = new ArrayList<>(VALID_TAGS);
         invalidTags.add(new JsonAdaptedTag(INVALID_TAG));
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, invalidTags);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, invalidTags, VALID_GRADES);
+        assertThrows(IllegalValueException.class, person::toModelType);
+    }
+
+    @Test
+    public void toModelType_invalidGrades_throwsIllegalValueException() {
+        List<JsonAdaptedGrade> invalidGrades = new ArrayList<>(VALID_GRADES);
+        invalidGrades.add(new JsonAdaptedGrade(INVALID_GRADE));
+        JsonAdaptedPerson person =
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_ADDRESS, VALID_TAGS, invalidGrades);
         assertThrows(IllegalValueException.class, person::toModelType);
     }
 
diff --git a/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java b/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
index 4584bd5044e..964a854a277 100644
--- a/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
+++ b/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
@@ -5,6 +5,7 @@
 import java.util.stream.Stream;
 
 import seedu.address.logic.commands.EditCommand.EditPersonDescriptor;
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -37,6 +38,7 @@ public EditPersonDescriptorBuilder(Person person) {
         descriptor.setEmail(person.getEmail());
         descriptor.setAddress(person.getAddress());
         descriptor.setTags(person.getTags());
+        descriptor.setGrades(person.getGrades());
     }
 
     /**
@@ -81,6 +83,16 @@ public EditPersonDescriptorBuilder withTags(String... tags) {
         return this;
     }
 
+    /**
+     * Parses the {@code grades} into a {@code Set<Grade>} and set it to the {@code EditPersonDescriptor}
+     * that we are building.
+     */
+    public EditPersonDescriptorBuilder withGrades(String... grades) {
+        Set<Grade> gradeSet = Stream.of(grades).map(Grade::new).collect(Collectors.toSet());
+        descriptor.setGrades(gradeSet);
+        return this;
+    }
+
     public EditPersonDescriptor build() {
         return descriptor;
     }
diff --git a/src/test/java/seedu/address/testutil/PersonBuilder.java b/src/test/java/seedu/address/testutil/PersonBuilder.java
index 6be381d39ba..34e3e28d05a 100644
--- a/src/test/java/seedu/address/testutil/PersonBuilder.java
+++ b/src/test/java/seedu/address/testutil/PersonBuilder.java
@@ -3,6 +3,7 @@
 import java.util.HashSet;
 import java.util.Set;
 
+import seedu.address.model.grade.Grade;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -26,6 +27,7 @@ public class PersonBuilder {
     private Email email;
     private Address address;
     private Set<Tag> tags;
+    private Set<Grade> grades;
 
     /**
      * Creates a {@code PersonBuilder} with the default details.
@@ -36,6 +38,7 @@ public PersonBuilder() {
         email = new Email(DEFAULT_EMAIL);
         address = new Address(DEFAULT_ADDRESS);
         tags = new HashSet<>();
+        grades = new HashSet<>();
     }
 
     /**
@@ -47,6 +50,7 @@ public PersonBuilder(Person personToCopy) {
         email = personToCopy.getEmail();
         address = personToCopy.getAddress();
         tags = new HashSet<>(personToCopy.getTags());
+        grades = new HashSet<>(personToCopy.getGrades());
     }
 
     /**
@@ -65,6 +69,14 @@ public PersonBuilder withTags(String ... tags) {
         return this;
     }
 
+    /**
+     * Parses the {@code grades} into a {@code Set<Grades>} and set it to the {@code Person} that we are building.
+     */
+    public PersonBuilder withGrades(String ... grades) {
+        this.grades = SampleDataUtil.getGradeSet(grades);
+        return this;
+    }
+
     /**
      * Sets the {@code Address} of the {@code Person} that we are building.
      */
@@ -90,7 +102,7 @@ public PersonBuilder withEmail(String email) {
     }
 
     public Person build() {
-        return new Person(name, phone, email, address, tags);
+        return new Person(name, phone, email, address, tags, grades);
     }
 
 }
diff --git a/src/test/java/seedu/address/testutil/PersonUtil.java b/src/test/java/seedu/address/testutil/PersonUtil.java
index 90849945183..d84fb4656df 100644
--- a/src/test/java/seedu/address/testutil/PersonUtil.java
+++ b/src/test/java/seedu/address/testutil/PersonUtil.java
@@ -2,6 +2,7 @@
 
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_GRADE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_TAG;
@@ -37,6 +38,9 @@ public static String getPersonDetails(Person person) {
         person.getTags().stream().forEach(
             s -> sb.append(PREFIX_TAG + s.tagName + " ")
         );
+        person.getGrades().stream().forEach(
+                s -> sb.append(PREFIX_GRADE + s.testAndGrade + " ")
+        );
         return sb.toString();
     }
 
diff --git a/src/test/java/seedu/address/testutil/TypicalPersons.java b/src/test/java/seedu/address/testutil/TypicalPersons.java
index fec76fb7129..39b960b2b35 100644
--- a/src/test/java/seedu/address/testutil/TypicalPersons.java
+++ b/src/test/java/seedu/address/testutil/TypicalPersons.java
@@ -4,6 +4,7 @@
 import static seedu.address.logic.commands.CommandTestUtil.VALID_ADDRESS_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_GRADE_CA1_100;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_AMY;
@@ -26,11 +27,14 @@ public class TypicalPersons {
     public static final Person ALICE = new PersonBuilder().withName("Alice Pauline")
             .withAddress("123, Jurong West Ave 6, #08-111").withEmail("alice@example.com")
             .withPhone("94351253")
-            .withTags("friends").build();
+            .withTags("friends")
+            .withGrades("ca1: 20")
+            .build();
     public static final Person BENSON = new PersonBuilder().withName("Benson Meier")
             .withAddress("311, Clementi Ave 2, #02-25")
             .withEmail("johnd@example.com").withPhone("98765432")
-            .withTags("owesMoney", "friends").build();
+            .withTags("owesMoney", "friends")
+            .withGrades("ca1: 90").build();
     public static final Person CARL = new PersonBuilder().withName("Carl Kurz").withPhone("95352563")
             .withEmail("heinz@example.com").withAddress("wall street").build();
     public static final Person DANIEL = new PersonBuilder().withName("Daniel Meier").withPhone("87652533")
@@ -50,7 +54,8 @@ public class TypicalPersons {
 
     // Manually added - Person's details found in {@code CommandTestUtil}
     public static final Person AMY = new PersonBuilder().withName(VALID_NAME_AMY).withPhone(VALID_PHONE_AMY)
-            .withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY).withTags(VALID_TAG_FRIEND).build();
+            .withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY).withTags(VALID_TAG_FRIEND)
+            .withGrades(VALID_GRADE_CA1_100).build();
     public static final Person BOB = new PersonBuilder().withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
             .withEmail(VALID_EMAIL_BOB).withAddress(VALID_ADDRESS_BOB).withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
             .build();