diff --git a/journal/models/mark.py b/journal/models/mark.py
index d3992051..b70bd915 100644
--- a/journal/models/mark.py
+++ b/journal/models/mark.py
@@ -125,6 +125,15 @@ class Mark:
     def tags(self) -> list[str]:
         return self.owner.tag_manager.get_item_tags(self.item)
 
+    @cached_property
+    def tag_text(self) -> str:
+        tags = [f"#{t}" for t in self.tags]
+        appending = self.owner.user.preference.mastodon_append_tag
+        if appending:
+            tags.append(appending)
+        tag_text = f"\n{' '.join(tags)}\n" if tags else ""
+        return tag_text
+
     @cached_property
     def rating(self):
         return Rating.objects.filter(owner=self.owner, item=self.item).first()
diff --git a/journal/models/tag.py b/journal/models/tag.py
index 4d481eca..1eeba59a 100644
--- a/journal/models/tag.py
+++ b/journal/models/tag.py
@@ -55,13 +55,13 @@ class Tag(List):
 
     @staticmethod
     def cleanup_title(title, replace=True):
-        t = re.sub(r"\s+", " ", title.strip())
-        return "_" if not title and replace else t
+        t = re.sub(r"\s+", " ", title.rstrip().lstrip("# "))
+        return "_" if not t and replace else t
 
     @staticmethod
     def deep_cleanup_title(title):
         """Remove all non-word characters, only for public index purpose"""
-        return re.sub(r"\W+", " ", title).strip()
+        return re.sub(r"\W+", " ", title).rstrip().lstrip("# ").lower() or "_"
 
 
 class TagManager:
@@ -78,7 +78,7 @@ class TagManager:
             [
                 t
                 for t in set(map(lambda t: Tag.deep_cleanup_title(t["title"]), tags))
-                if t
+                if t and t != "_"
             ]
         )
         return tag_titles
diff --git a/journal/tests.py b/journal/tests.py
index c436eb3f..18bc2fee 100644
--- a/journal/tests.py
+++ b/journal/tests.py
@@ -144,6 +144,10 @@ class TagTest(TestCase):
         self.user2 = User.register(email="x@b.com", username="user2")
         self.user3 = User.register(email="y@b.com", username="user3")
 
+    def test_cleanup(self):
+        self.assertEqual(Tag.cleanup_title("# "), "_")
+        self.assertEqual(Tag.deep_cleanup_title("# C "), "c")
+
     def test_user_tag(self):
         t1 = "tag 1"
         t2 = "tag 2"
diff --git a/mastodon/api.py b/mastodon/api.py
index 91c03a4c..cec9d0f2 100644
--- a/mastodon/api.py
+++ b/mastodon/api.py
@@ -590,23 +590,13 @@ def share_mark(mark, post_as_new=False):
 
     user = mark.owner.user
     visibility = get_toot_visibility(mark.visibility, user)
-    tags = (
-        "\n"
-        + user.preference.mastodon_append_tag.replace(
-            "[category]", str(ItemCategory(mark.item.category).label)
-        )
-        if user.preference.mastodon_append_tag
-        else ""
-    )
     site = MastodonApplication.objects.filter(domain_name=user.mastodon_site).first()
     stars = rating_to_emoji(
         mark.rating_grade,
         site.star_mode if site else 0,
     )
     spoiler_text, txt = get_spoiler_text(mark.comment_text or "", mark.item)
-    content = (
-        f"{mark.get_action_for_feed()} {stars}\n{mark.item.absolute_url}\n{txt}{tags}"
-    )
+    content = f"{mark.get_action_for_feed()} {stars}\n{mark.item.absolute_url}\n{txt}{mark.tag_text}"
     update_id = (
         None
         if post_as_new
diff --git a/takahe/utils.py b/takahe/utils.py
index 5470b4af..6ff616f0 100644
--- a/takahe/utils.py
+++ b/takahe/utils.py
@@ -686,19 +686,11 @@ class Takahe:
         from catalog.common import ItemCategory
 
         user = mark.owner.user
-        tags = (
-            user.preference.mastodon_append_tag.replace(
-                "[category]", str(ItemCategory(mark.item.category).label)
-            )
-            + "\n"
-            if user.preference.mastodon_append_tag
-            else ""
-        )
         stars = _rating_to_emoji(mark.rating_grade, 1)
         item_link = f"{settings.SITE_INFO['site_url']}/~neodb~{mark.item.url}"
         pre_conetent = mark.get_action_for_feed(item_link=item_link)
         spoiler, txt = Takahe.get_spoiler_text(mark.comment_text, mark.item)
-        content = f"{stars} \n{txt}\n{tags}"
+        content = f"{stars} \n{txt}\n{mark.tag_text}"
         data = {
             "object": {
                 "tag": [mark.item.ap_object_ref],