diff --git a/src/character/models/character.py b/src/character/models/character.py
index 6eeceee..21fa0e8 100644
--- a/src/character/models/character.py
+++ b/src/character/models/character.py
@@ -14,6 +14,7 @@ from django_extensions.db.models import TimeStampedModel
 from character.models import Capability, Path
 from character.models.dice import Dice
 from character.models.equipment import Weapon
+from character.models.utils import cache_on_instance
 from common.models import DocumentedModel, UniquelyNamedModel
 
 
@@ -471,12 +472,15 @@ class Character(models.Model):
             pk__in=self.states.all().values_list("pk", flat=True),
         )
 
+    @cache_on_instance()
     def managed_by(self, user):
         return self in Character.objects.managed_by(user)
 
+    @cache_on_instance()
     def mastered_by(self, user):
         return self in Character.objects.mastered_by(user)
 
+    @cache_on_instance()
     def owned_by(self, user):
         return self in Character.objects.owned_by(user)
 
diff --git a/src/character/models/utils.py b/src/character/models/utils.py
new file mode 100644
index 0000000..426f5f3
--- /dev/null
+++ b/src/character/models/utils.py
@@ -0,0 +1,38 @@
+import functools
+
+
+def cache_on_instance():
+    def wrapper(func):
+        @functools.wraps(func)
+        def inner(self, arg):
+            cache_name = func.__name__
+            if (cached := _get_cache_value(self, cache_name, arg)) is not None:
+                return cached
+            res = func(self, arg)
+            _set_cache_value(self, cache_name, arg, res)
+            return res
+
+        return inner
+
+    return wrapper
+
+
+def _get_cache_value(obj, cache_name: str, key: str) -> any:
+    cache_name += "_cache"
+    cache = getattr(obj, cache_name, None)
+    if cache is None:
+        cache = {}
+        setattr(obj, cache_name, cache)
+        return None
+
+    return cache.get(key)
+
+
+def _set_cache_value(obj, cache_name: str, key: str, value: any):
+    cache_name += "_cache"
+    cache = getattr(obj, cache_name)
+    if cache is None:
+        cache = {}
+        setattr(obj, cache_name, cache)
+
+    cache[key] = value