diff --git a/core/__pycache__/admin.cpython-311.pyc b/core/__pycache__/admin.cpython-311.pyc
index cd6f855..e20332c 100644
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diff --git a/core/__pycache__/models.cpython-311.pyc b/core/__pycache__/models.cpython-311.pyc
index 9aa598b..6055c0d 100644
Binary files a/core/__pycache__/models.cpython-311.pyc and b/core/__pycache__/models.cpython-311.pyc differ
diff --git a/core/admin.py b/core/admin.py
index 8c38f3f..46eb905 100644
--- a/core/admin.py
+++ b/core/admin.py
@@ -1,3 +1,6 @@
 from django.contrib import admin
+from .models import MoodEntry, Activity, Mission
 
-# Register your models here.
+admin.site.register(MoodEntry)
+admin.site.register(Activity)
+admin.site.register(Mission)
\ No newline at end of file
diff --git a/core/migrations/0001_initial.py b/core/migrations/0001_initial.py
new file mode 100644
index 0000000..47d803a
--- /dev/null
+++ b/core/migrations/0001_initial.py
@@ -0,0 +1,49 @@
+# Generated by Django 5.2.7 on 2025-12-22 18:33
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Activity',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('icon', models.CharField(max_length=50)),
+                ('category', models.CharField(choices=[('Social', 'Social'), ('Health', 'Health'), ('Hobbies', 'Hobbies'), ('Obligation', 'Obligation')], max_length=50)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Mission',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(max_length=255)),
+                ('description', models.TextField()),
+                ('trigger_mood_score', models.IntegerField()),
+                ('is_active', models.BooleanField(default=True)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='MoodEntry',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('date_time', models.DateTimeField(auto_now_add=True)),
+                ('mood_score', models.IntegerField()),
+                ('note', models.TextField(blank=True, null=True)),
+                ('color_code', models.CharField(max_length=7)),
+                ('activities', models.ManyToManyField(to='core.activity')),
+                ('mission', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='core.mission')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+    ]
diff --git a/core/migrations/__pycache__/0001_initial.cpython-311.pyc b/core/migrations/__pycache__/0001_initial.cpython-311.pyc
new file mode 100644
index 0000000..0eeb037
Binary files /dev/null and b/core/migrations/__pycache__/0001_initial.cpython-311.pyc differ
diff --git a/core/models.py b/core/models.py
index 71a8362..16f0a31 100644
--- a/core/models.py
+++ b/core/models.py
@@ -1,3 +1,38 @@
 from django.db import models
+from django.contrib.auth.models import User
 
-# Create your models here.
+
+class Activity(models.Model):
+    class Category(models.TextChoices):
+        SOCIAL = 'Social'
+        HEALTH = 'Health'
+        HOBBIES = 'Hobbies'
+        OBLIGATION = 'Obligation'
+
+    name = models.CharField(max_length=255)
+    icon = models.CharField(max_length=50)
+    category = models.CharField(max_length=50, choices=Category.choices)
+
+    def __str__(self):
+        return self.name
+
+class Mission(models.Model):
+    title = models.CharField(max_length=255)
+    description = models.TextField()
+    trigger_mood_score = models.IntegerField()
+    is_active = models.BooleanField(default=True)
+
+    def __str__(self):
+        return self.title
+
+class MoodEntry(models.Model):
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    date_time = models.DateTimeField(auto_now_add=True)
+    mood_score = models.IntegerField()
+    note = models.TextField(blank=True, null=True)
+    color_code = models.CharField(max_length=7)
+    activities = models.ManyToManyField(Activity)
+    mission = models.ForeignKey(Mission, on_delete=models.SET_NULL, null=True, blank=True)
+
+    def __str__(self):
+        return f'{self.user.username} - {self.date_time.strftime("%Y-%m-%d")}'
\ No newline at end of file
diff --git a/core/templates/base.html b/core/templates/base.html
index 1e7e5fb..98c16d8 100644
--- a/core/templates/base.html
+++ b/core/templates/base.html
@@ -19,6 +19,18 @@
 </head>
 
 <body>
+  <nav class="navbar navbar-expand-lg navbar-light bg-light">
+    <div class="container-fluid">
+      <a class="navbar-brand" href="/">PixelMinds</a>
+      <div class="collapse navbar-collapse" id="navbarNav">
+        <ul class="navbar-nav">
+          <li class="nav-item">
+            <a class="nav-link" href="/admin">Admin</a>
+          </li>
+        </ul>
+      </div>
+    </div>
+  </nav>
   {% block content %}{% endblock %}
 </body>