diff --git a/functions/join_meshes.py b/functions/join_meshes.py
deleted file mode 100644
index 09776ae..0000000
--- a/functions/join_meshes.py
+++ /dev/null
@@ -1,132 +0,0 @@
-import bpy
-from typing import List, Optional, Set
-from bpy.types import Operator, Context, Object
-from ..core.register import register_wrap
-from ..core.common import fix_uv_coordinates, get_selected_armature, is_valid_armature, select_current_armature, get_all_meshes, init_progress, update_progress, finish_progress
-from ..functions.translations import t
-
-@register_wrap
-class AvatarToolKit_OT_JoinAllMeshes(Operator):
-    bl_idname = "avatar_toolkit.join_all_meshes"
-    bl_label = t("Optimization.join_all_meshes.label")
-    bl_description = t("Optimization.join_all_meshes.desc")
-    bl_options = {'REGISTER', 'UNDO'}
-
-    @classmethod
-    def poll(cls, context: Context) -> bool:
-        armature = get_selected_armature(context)
-        return armature is not None and is_valid_armature(armature)
-
-    def execute(self, context: Context) -> Set[str]:
-        try:
-            self.join_all_meshes(context)
-            return {'FINISHED'}
-        except Exception as e:
-            self.report({'ERROR'}, f"{t('Optimization.join_error')}: {str(e)}")
-            return {'CANCELLED'}
-
-    def join_all_meshes(self, context: Context) -> None:
-        if not select_current_armature(context):
-            raise ValueError(t("Optimization.no_armature_selected"))
-
-        armature = get_selected_armature(context)
-        bpy.ops.object.mode_set(mode='OBJECT')
-        bpy.ops.object.select_all(action='DESELECT')
-
-        meshes: List[Object] = get_all_meshes(context)
-        if not meshes:
-            raise ValueError(t("Optimization.no_meshes_found"))
-
-        init_progress(context, 5)  # 5 steps in total
-
-        update_progress(self, context, t("Optimization.selecting_meshes"))
-        for mesh in meshes:
-            mesh.select_set(True)
-
-        if bpy.context.selected_objects:
-            bpy.context.view_layer.objects.active = bpy.context.selected_objects[0]
-            
-            update_progress(self, context, t("Optimization.joining_meshes"))
-            try:
-                bpy.ops.object.join()
-            except RuntimeError as e:
-                raise RuntimeError(f"{t('Optimization.join_operation_failed')}: {str(e)}")
-
-            update_progress(self, context, t("Optimization.applying_transforms"))
-            try:
-                bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
-            except RuntimeError as e:
-                raise RuntimeError(f"{t('Optimization.transform_apply_failed')}: {str(e)}")
-
-            update_progress(self, context, t("Optimization.fixing_uv_coordinates"))
-            fix_uv_coordinates(context)
-            
-            update_progress(self, context, t("Optimization.finalizing"))
-            bpy.ops.object.mode_set(mode='OBJECT')
-            bpy.ops.object.select_all(action='DESELECT')
-            self.report({'INFO'}, t("Optimization.meshes_joined"))
-        else:
-            raise ValueError(t("Optimization.no_mesh_selected"))
-
-        context.view_layer.objects.active = armature
-        finish_progress(context)
-
-@register_wrap
-class AvatarToolKit_OT_JoinSelectedMeshes(Operator):
-    bl_idname = "avatar_toolkit.join_selected_meshes"
-    bl_label = t("Optimization.join_selected_meshes.label")
-    bl_description = t("Optimization.join_selected_meshes.desc")
-    bl_options = {'REGISTER', 'UNDO'}
-
-    @classmethod
-    def poll(cls, context: Context) -> bool:
-        return context.mode == 'OBJECT' and len([obj for obj in context.selected_objects if obj.type == 'MESH']) > 1
-
-    def execute(self, context: Context) -> Set[str]:
-        try:
-            self.join_selected_meshes(context)
-            return {'FINISHED'}
-        except Exception as e:
-            self.report({'ERROR'}, f"{t('Optimization.join_error')}: {str(e)}")
-            return {'CANCELLED'}
-
-    def join_selected_meshes(self, context: Context) -> None:
-        selected_objects: List[Object] = [obj for obj in bpy.context.selected_objects if obj.type == 'MESH']
-
-        if len(selected_objects) < 2:
-            raise ValueError(t("Optimization.select_at_least_two_meshes"))
-
-        init_progress(context, 5)  # 5 steps in total
-
-        update_progress(self, context, t("Optimization.preparing_meshes"))
-        bpy.ops.object.mode_set(mode='OBJECT')
-        bpy.ops.object.select_all(action='DESELECT')
-
-        update_progress(self, context, t("Optimization.selecting_meshes"))
-        for obj in selected_objects:
-            obj.select_set(True)
-
-        if bpy.context.selected_objects:
-            bpy.context.view_layer.objects.active = bpy.context.selected_objects[0]
-            
-            update_progress(self, context, t("Optimization.joining_meshes"))
-            try:
-                bpy.ops.object.join()
-            except RuntimeError as e:
-                raise RuntimeError(f"{t('Optimization.join_operation_failed')}: {str(e)}")
-
-            update_progress(self, context, t("Optimization.applying_transforms"))
-            try:
-                bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
-            except RuntimeError as e:
-                raise RuntimeError(f"{t('Optimization.transform_apply_failed')}: {str(e)}")
-
-            update_progress(self, context, t("Optimization.fixing_uv_coordinates"))
-            fix_uv_coordinates(context)
-            bpy.ops.object.mode_set(mode='OBJECT')
-            bpy.ops.object.select_all(action='DESELECT')
-            self.report({'INFO'}, t("Optimization.selected_meshes_joined"))
-        else:
-            raise ValueError(t("Optimization.no_mesh_selected"))
-
-        finish_progress(context)
diff --git a/functions/mesh_tools.py b/functions/mesh_tools.py
index 1ebd43f..426dc54 100644
--- a/functions/mesh_tools.py
+++ b/functions/mesh_tools.py
@@ -1,7 +1,8 @@
 import numpy as np
 import bpy
-from bpy.types import Context
-from ..core.common import get_selected_armature, get_all_meshes, is_valid_armature, apply_shapekey_to_basis, has_shapekeys
+from typing import List, Optional, Set
+from bpy.types import Operator, Context, Object
+from ..core.common import fix_uv_coordinates, get_selected_armature, get_all_meshes, is_valid_armature, apply_shapekey_to_basis, has_shapekeys, select_current_armature, init_progress, update_progress, finish_progress
 from ..functions.translations import t
 from ..core.register import register_wrap
 
@@ -76,4 +77,130 @@ class AvatarToolkit_OT_ApplyShapeKey(bpy.types.Operator):
             return {'FINISHED'}
         else:
             self.report({'ERROR'}, t("Tools.apply_shape_key.error"))
-            return {'FINISHED'}
\ No newline at end of file
+            return {'FINISHED'}
+
+@register_wrap
+class AvatarToolKit_OT_JoinAllMeshes(Operator):
+    bl_idname = "avatar_toolkit.join_all_meshes"
+    bl_label = t("Optimization.join_all_meshes.label")
+    bl_description = t("Optimization.join_all_meshes.desc")
+    bl_options = {'REGISTER', 'UNDO'}
+
+    @classmethod
+    def poll(cls, context: Context) -> bool:
+        armature = get_selected_armature(context)
+        return armature is not None and is_valid_armature(armature)
+
+    def execute(self, context: Context) -> Set[str]:
+        try:
+            self.join_all_meshes(context)
+            return {'FINISHED'}
+        except Exception as e:
+            self.report({'ERROR'}, f"{t('Optimization.join_error')}: {str(e)}")
+            return {'CANCELLED'}
+
+    def join_all_meshes(self, context: Context) -> None:
+        if not select_current_armature(context):
+            raise ValueError(t("Optimization.no_armature_selected"))
+
+        armature = get_selected_armature(context)
+        bpy.ops.object.mode_set(mode='OBJECT')
+        bpy.ops.object.select_all(action='DESELECT')
+
+        meshes: List[Object] = get_all_meshes(context)
+        if not meshes:
+            raise ValueError(t("Optimization.no_meshes_found"))
+
+        init_progress(context, 5)  # 5 steps in total
+
+        update_progress(self, context, t("Optimization.selecting_meshes"))
+        for mesh in meshes:
+            mesh.select_set(True)
+
+        if bpy.context.selected_objects:
+            bpy.context.view_layer.objects.active = bpy.context.selected_objects[0]
+            
+            update_progress(self, context, t("Optimization.joining_meshes"))
+            try:
+                bpy.ops.object.join()
+            except RuntimeError as e:
+                raise RuntimeError(f"{t('Optimization.join_operation_failed')}: {str(e)}")
+
+            update_progress(self, context, t("Optimization.applying_transforms"))
+            try:
+                bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
+            except RuntimeError as e:
+                raise RuntimeError(f"{t('Optimization.transform_apply_failed')}: {str(e)}")
+
+            update_progress(self, context, t("Optimization.fixing_uv_coordinates"))
+            fix_uv_coordinates(context)
+            
+            update_progress(self, context, t("Optimization.finalizing"))
+            bpy.ops.object.mode_set(mode='OBJECT')
+            bpy.ops.object.select_all(action='DESELECT')
+            self.report({'INFO'}, t("Optimization.meshes_joined"))
+        else:
+            raise ValueError(t("Optimization.no_mesh_selected"))
+
+        context.view_layer.objects.active = armature
+        finish_progress(context)
+
+@register_wrap
+class AvatarToolKit_OT_JoinSelectedMeshes(Operator):
+    bl_idname = "avatar_toolkit.join_selected_meshes"
+    bl_label = t("Optimization.join_selected_meshes.label")
+    bl_description = t("Optimization.join_selected_meshes.desc")
+    bl_options = {'REGISTER', 'UNDO'}
+
+    @classmethod
+    def poll(cls, context: Context) -> bool:
+        return context.mode == 'OBJECT' and len([obj for obj in context.selected_objects if obj.type == 'MESH']) > 1
+
+    def execute(self, context: Context) -> Set[str]:
+        try:
+            self.join_selected_meshes(context)
+            return {'FINISHED'}
+        except Exception as e:
+            self.report({'ERROR'}, f"{t('Optimization.join_error')}: {str(e)}")
+            return {'CANCELLED'}
+
+    def join_selected_meshes(self, context: Context) -> None:
+        selected_objects: List[Object] = [obj for obj in bpy.context.selected_objects if obj.type == 'MESH']
+
+        if len(selected_objects) < 2:
+            raise ValueError(t("Optimization.select_at_least_two_meshes"))
+
+        init_progress(context, 5)  # 5 steps in total
+
+        update_progress(self, context, t("Optimization.preparing_meshes"))
+        bpy.ops.object.mode_set(mode='OBJECT')
+        bpy.ops.object.select_all(action='DESELECT')
+
+        update_progress(self, context, t("Optimization.selecting_meshes"))
+        for obj in selected_objects:
+            obj.select_set(True)
+
+        if bpy.context.selected_objects:
+            bpy.context.view_layer.objects.active = bpy.context.selected_objects[0]
+            
+            update_progress(self, context, t("Optimization.joining_meshes"))
+            try:
+                bpy.ops.object.join()
+            except RuntimeError as e:
+                raise RuntimeError(f"{t('Optimization.join_operation_failed')}: {str(e)}")
+
+            update_progress(self, context, t("Optimization.applying_transforms"))
+            try:
+                bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
+            except RuntimeError as e:
+                raise RuntimeError(f"{t('Optimization.transform_apply_failed')}: {str(e)}")
+
+            update_progress(self, context, t("Optimization.fixing_uv_coordinates"))
+            fix_uv_coordinates(context)
+            bpy.ops.object.mode_set(mode='OBJECT')
+            bpy.ops.object.select_all(action='DESELECT')
+            self.report({'INFO'}, t("Optimization.selected_meshes_joined"))
+        else:
+            raise ValueError(t("Optimization.no_mesh_selected"))
+
+        finish_progress(context)
\ No newline at end of file
diff --git a/ui/mmd_options.py b/ui/mmd_options.py
index 1b609b1..d3e1eb1 100644
--- a/ui/mmd_options.py
+++ b/ui/mmd_options.py
@@ -3,7 +3,7 @@ from ..core.register import register_wrap
 from .panel import AvatarToolKit_PT_AvatarToolkitPanel, CATEGORY_NAME
 from ..functions.translations import t
 from ..functions.mmd_functions import *
-from ..functions.join_meshes import AvatarToolKit_OT_JoinAllMeshes
+from ..functions.mesh_tools import AvatarToolKit_OT_JoinAllMeshes
 from ..functions.combine_materials import AvatarToolKit_OT_CombineMaterials
 from ..functions.additional_tools import AvatarToolKit_OT_ApplyTransforms