diff --git a/mmd_tools/core/model.py b/mmd_tools/core/model.py
index 5cf7278..6802d79 100644
--- a/mmd_tools/core/model.py
+++ b/mmd_tools/core/model.py
@@ -607,12 +607,26 @@ def create(name: str, name_e: str = "", scale: float = 1, obj_name: Optional[str
 
         if add_root_bone:
             bone_name = "全ての親"
+            bone_name_english = "Root"
+
+            # Create the root bone
             with bpyutils.edit_object(armature_object) as data:
                 bone = data.edit_bones.new(name=bone_name)
-                bone.head = [0.0, 0.0, 0.0]
-                bone.tail = [0.0, 0.0, getattr(root, Props.empty_display_size)]
-            armature_object.pose.bones[bone_name].mmd_bone.name_j = bone_name
-            armature_object.pose.bones[bone_name].mmd_bone.name_e = "Root"
+                bone.head = (0.0, 0.0, 0.0)
+                bone.tail = (0.0, 0.0, getattr(root, Props.empty_display_size))
+
+            # Set MMD bone properties
+            pose_bone = armature_object.pose.bones[bone_name]
+            pose_bone.mmd_bone.name_j = bone_name
+            pose_bone.mmd_bone.name_e = bone_name_english
+
+            # Create a bone collection named "Root"
+            bone_collection_name = bone_name_english
+            bone_collection = armature_object.data.collections.new(name=bone_collection_name)
+
+            # Assign the new bone to the bone collection
+            data_bone = armature_object.data.bones[bone_name]
+            bone_collection.assign(data_bone)
 
         FnContext.set_active_and_select_single_object(context, root)
         return Model(root)
diff --git a/mmd_tools/core/pmx/exporter.py b/mmd_tools/core/pmx/exporter.py
index 2789551..ab33c49 100644
--- a/mmd_tools/core/pmx/exporter.py
+++ b/mmd_tools/core/pmx/exporter.py
@@ -376,7 +376,12 @@ def __to_pmx_axis(axis, pose_bone):
 
                 pmx_bone.location = __to_pmx_location(p_bone.head)
                 pmx_bone.parent = bone.parent
-                pmx_bone.visible = not bone.hide and any(c.is_visible for c in bone.collections)
+                # Determine bone visibility: visible if not hidden and either has no collections or belongs to at least one visible collection
+                # This logic is the same as Blender's
+                pmx_bone.visible = (
+                    not bone.hide
+                    and (not bone.collections or any(collection.is_visible for collection in bone.collections))
+                )
                 pmx_bone.isControllable = mmd_bone.is_controllable
                 pmx_bone.isMovable = not all(p_bone.lock_location)
                 pmx_bone.isRotatable = not all(p_bone.lock_rotation)