diff --git a/CHANGELOG.md b/CHANGELOG.md
index e044ab9..5ec2ed8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,9 +9,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
-- none
-
-
+- Achievements
+  - added `IAchievementNf` class.
+  - added `NotificationAchievement` class.
+  - added `Achievement` class.
+  - added `get_achievements` method at `UserActions` class.
+  - added `achievements` property at `UserDetailed` class.
 
 ## [0.4.0] 2023-01-18
 
diff --git a/mipac/actions/user.py b/mipac/actions/user.py
index e308461..a590f55 100644
--- a/mipac/actions/user.py
+++ b/mipac/actions/user.py
@@ -4,7 +4,7 @@ from typing import TYPE_CHECKING, AsyncIterator, Literal, Optional
 
 from mipac.errors.base import NotExistRequiredData, ParameterError
 from mipac.http import HTTPClient, Route
-from mipac.models.user import LiteUser, UserDetailed
+from mipac.models.user import LiteUser, UserDetailed, Achievement
 from mipac.util import cache, check_multi_arg, remove_dict_empty
 
 if TYPE_CHECKING:
@@ -30,7 +30,9 @@ class UserActions:
         ログインしているユーザーの情報を取得します
         """
 
-        res = await self.__session.request(Route('POST', '/api/i'), auth=True)
+        res = await self.__session.request(
+            Route('POST', '/api/i'), auth=True, lower=True,
+        )
         return UserDetailed(res, client=self.__client)  # TODO: 自分用のクラスに変更する
 
     def get_profile_link(
@@ -309,3 +311,23 @@ class UserActions:
             else LiteUser(user, client=self.__client)
             for user in res
         ]
+
+    async def get_achievements(
+        self,
+        user_id: str | None = None
+    ) -> list[Achievement]:
+        """ Get achievements of user. """
+
+        user_id = user_id or self.__user and self.__user.id
+
+        if not user_id:
+            raise ParameterError('user_id is required')
+
+        data = {
+            'userId': user_id,
+        }
+        res = await self.__session.request(
+            Route('POST', '/api/users/achievements'),
+            json=data, auth=True, lower=True,
+        )
+        return [Achievement(i) for i in res]
diff --git a/mipac/models/notification.py b/mipac/models/notification.py
index 03737a9..0ea6ccc 100644
--- a/mipac/models/notification.py
+++ b/mipac/models/notification.py
@@ -15,6 +15,7 @@ if TYPE_CHECKING:
         INoteNf,
         IPollEndNf,
         IReactionNf,
+        IAchievementNf,
     )
 
 
@@ -141,3 +142,16 @@ class NotificationReaction(Notification):
     @property
     def reaction(self) -> str:
         return self.__notification['reaction']
+
+
+class NotificationAchievement(Notification):
+    def __init__(
+        self, notification: IAchievementNf, *, client: ClientManager,
+    ) -> None:
+        super().__init__(notification, client=client)
+        self.__notification: IAchievementNf = notification
+        self.__client: ClientManager = client
+
+    @property
+    def achievement(self) -> str:
+        return self.__notification['achievement']
diff --git a/mipac/models/user.py b/mipac/models/user.py
index 5340c00..fa6f619 100644
--- a/mipac/models/user.py
+++ b/mipac/models/user.py
@@ -5,12 +5,13 @@ from typing import TYPE_CHECKING, Literal
 from mipac.models.lite.user import LiteUser
 from mipac.models.note import Note
 from mipac.types.page import IPage
-from mipac.types.user import IFollowRequest, IUserDetailed, IUserDetailedField
+from mipac.types.user import IFollowRequest, IUserDetailed, \
+    IUserDetailedField, IAchievement
 
 if TYPE_CHECKING:
     from mipac.manager.client import ClientManager
 
-__all__ = ('UserDetailed', 'FollowRequest', 'LiteUser')
+__all__ = ('UserDetailed', 'FollowRequest', 'LiteUser', 'Achievement')
 
 
 class FollowRequest:
@@ -31,6 +32,19 @@ class FollowRequest:
         return LiteUser(self.__request['followee'], client=self.__client)
 
 
+class Achievement:
+    def __init__(self, detail: IAchievement):
+        self.__detail: IAchievement = detail
+
+    @property
+    def name(self) -> str:
+        return self.__detail['name']
+
+    @property
+    def unlocked_at(self) -> int:
+        return self.__detail['unlocked_at']
+
+
 class UserDetailed(LiteUser):
     __slots__ = (
         '__detail',
@@ -41,6 +55,10 @@ class UserDetailed(LiteUser):
         super().__init__(user=user, client=client)
         self.__detail = user
 
+    @property
+    def achievements(self) -> list[Achievement]:
+        return [Achievement(i) for i in self.__detail.get('achievements', [])]
+
     @property
     def fields(self) -> list[IUserDetailedField]:
         return self.__detail['fields']
@@ -178,6 +196,10 @@ class UserDetailed(LiteUser):
     def location(self) -> str | None:
         return self.__detail.get('location')
 
+    @property
+    def logged_in_days(self) -> int | None:
+        return self.__detail.get('logged_in_days')
+
     @property
     def pinned_page(self) -> IPage | None:
         return self.__detail.get('pinned_page')
diff --git a/mipac/types/endpoints.py b/mipac/types/endpoints.py
index b88f242..6ef8960 100644
--- a/mipac/types/endpoints.py
+++ b/mipac/types/endpoints.py
@@ -274,6 +274,7 @@ ENDPOINTS = Literal[
     '/api/test',
     '/api/username/available',
     '/api/users',
+    '/api/users/achievements',
     '/api/users/clips',
     '/api/users/followers',
     '/api/users/following',
diff --git a/mipac/types/notification.py b/mipac/types/notification.py
index 618a633..9602cee 100644
--- a/mipac/types/notification.py
+++ b/mipac/types/notification.py
@@ -40,3 +40,7 @@ class IReactionNf(INotification):
     user: ILiteUser
     user_id: str
     note: INote
+
+
+class IAchievementNf(INotification):
+    achievement: str
diff --git a/mipac/types/user.py b/mipac/types/user.py
index ff914dc..0216645 100644
--- a/mipac/types/user.py
+++ b/mipac/types/user.py
@@ -13,6 +13,7 @@ __all__ = (
     'ILiteUser',
     'IUserDetailed',
     'IUserDetailedField',
+    'IAchievement',
 )
 
 
@@ -25,6 +26,11 @@ class ISignin(TypedDict):
     success: bool
 
 
+class IAchievement(TypedDict):
+    name: str
+    unlocked_at: int
+
+
 class IUserRequired(TypedDict):
     id: str
     username: str
@@ -73,6 +79,7 @@ class IUserDetailedRequired(ILiteUser):
 
 
 class IUserDetailed(IUserDetailedRequired, total=False):
+    achievements: List[IAchievement]
     banner_blurhash: str
     banner_color: str
     banner_url: str
@@ -83,6 +90,7 @@ class IUserDetailed(IUserDetailedRequired, total=False):
     lang: str
     last_fetched_at: str
     location: str
+    logged_in_days: int
     pinned_page: IPage
     pinned_page_id: str
     updated_at: str
diff --git a/mipac/util.py b/mipac/util.py
index 1da4efe..02c848c 100644
--- a/mipac/util.py
+++ b/mipac/util.py
@@ -373,6 +373,11 @@ def upper_to_lower(
         field[default_key] = data[attr]
         if isinstance(field[default_key], dict) and nest:
             field[default_key] = upper_to_lower(field[default_key])
+        elif isinstance(field[default_key], list) and nest:
+            field[default_key] = [
+                upper_to_lower(i) if isinstance(i, dict)
+                else i for i in field[default_key]
+            ]
     return field