diff --git a/locales/en.yml b/locales/en.yml
index 2c6ed497..abfe232f 100644
--- a/locales/en.yml
+++ b/locales/en.yml
@@ -16,6 +16,9 @@ main_window:
 
   update_available: New version is here!
 
+  modal_message:
+    opened_config_window: The functionality is temporarily disabled until the settings window is closed.
+
 selectable_language_window:
   title_your_language: Select Your Language
   title_target_language: Select Target Language
diff --git a/locales/ja.yml b/locales/ja.yml
index 040bb36c..4b5f373a 100644
--- a/locales/ja.yml
+++ b/locales/ja.yml
@@ -16,6 +16,10 @@ main_window:
 
   update_available: 新しいバージョンが出ました！
 
+  modal_message:
+    opened_config_window: 設定画面が閉じられるまで、一時的に機能を停止しています。
+
+
 selectable_language_window:
   title_your_language: あなたの言語
   title_target_language: 相手の言語
diff --git a/view.py b/view.py
index e1f924ad..a49da319 100644
--- a/view.py
+++ b/view.py
@@ -53,6 +53,12 @@ class View():
             **common_args
         )
 
+        self.settings.modal_window = SimpleNamespace(
+            ctm=all_ctm.modal_window,
+            uism=all_uism.modal_window,
+            **common_args
+        )
+
         self.view_variable = SimpleNamespace(
             # Open Config Window
             CALLBACK_OPEN_CONFIG_WINDOW=None,
@@ -112,6 +118,9 @@ class View():
             VAR_UPDATE_AVAILABLE=StringVar(value=i18n.t("main_window.update_available")),
 
 
+            # Modal Window For Main Window
+            VAR_LABEL_MODAL_MESSAGE_FOR__MAIN_WINDOW=StringVar(value=i18n.t("main_window.modal_message.opened_config_window")),
+
             # Selectable Language Window
             VAR_TITLE_LABEL_SELECTABLE_LANGUAGE=StringVar(value=""),
             VAR_GO_BACK_LABEL_SELECTABLE_LANGUAGE=StringVar(value=i18n.t("selectable_language_window.go_back_button")),
diff --git a/vrct_gui/_CreateModalWindow.py b/vrct_gui/_CreateModalWindow.py
new file mode 100644
index 00000000..b54bad76
--- /dev/null
+++ b/vrct_gui/_CreateModalWindow.py
@@ -0,0 +1,49 @@
+from customtkinter import CTkToplevel, CTkFrame, CTkLabel, CTkFont
+
+class _CreateModalWindow(CTkToplevel):
+    def __init__(self, attach_window, settings, view_variable):
+        super().__init__()
+        self.withdraw()
+
+
+        self.title("")
+        self.overrideredirect(True)
+
+        self.wm_attributes("-alpha", 0.5)
+        self.wm_attributes("-toolwindow", True)
+
+        self.attach_window = attach_window
+
+
+        self.configure(fg_color="black")
+        self.protocol("WM_DELETE_WINDOW", lambda e: self.withdraw())
+
+        self.settings = settings
+        self._view_variable = view_variable
+
+
+        self.attach_window.update_idletasks()
+        self.x_pos = self.attach_window.winfo_rootx()
+        self.y_pos = self.attach_window.winfo_rooty()
+        self.width_new = self.attach_window.winfo_width()
+        self.height_new = self.attach_window.winfo_height()
+
+
+        self.geometry('{}x{}+{}+{}'.format(self.width_new, self.height_new, self.x_pos, self.y_pos))
+
+        self.rowconfigure(0,weight=1)
+        self.columnconfigure(0,weight=1)
+        self.modal_container = CTkFrame(self, corner_radius=0, fg_color="black", width=0, height=0)
+        self.modal_container.grid(row=0, column=0, sticky="nsew")
+
+
+        self.modal_container_label_wrapper = CTkLabel(
+            self.modal_container,
+            textvariable=self._view_variable.VAR_LABEL_MODAL_MESSAGE_FOR__MAIN_WINDOW,
+            height=0,
+            corner_radius=0,
+            font=CTkFont(family=self.settings.FONT_FAMILY, size=self.settings.uism.TEXT_FONT_SIZE, weight="normal"),
+            anchor="w",
+            text_color=self.settings.ctm.TEXT_COLOR,
+        )
+        self.modal_container_label_wrapper.place(relx=0.5, rely=0.5, anchor="center")
\ No newline at end of file
diff --git a/vrct_gui/ui_managers/ColorThemeManager.py b/vrct_gui/ui_managers/ColorThemeManager.py
index 2b5833ef..c712b2d4 100644
--- a/vrct_gui/ui_managers/ColorThemeManager.py
+++ b/vrct_gui/ui_managers/ColorThemeManager.py
@@ -5,6 +5,7 @@ class ColorThemeManager():
         self.main = SimpleNamespace()
         self.config_window = SimpleNamespace()
         self.selectable_language_window = SimpleNamespace()
+        self.modal_window = SimpleNamespace()
 
         # old one. But leave it here for now.
         # self.PRIMARY_100_COLOR = "#c4eac1"
@@ -207,6 +208,9 @@ class ColorThemeManager():
         self.selectable_language_window.LANGUAGE_BUTTON_BG_CLICKED_COLOR = self.DARK_888_COLOR
 
 
+        # Modal Window (Main Window)
+        self.modal_window.TEXT_COLOR = self.LIGHT_100_COLOR
+
 
         # Common
         self.config_window.BASIC_TEXT_COLOR = self.main.BASIC_TEXT_COLOR
diff --git a/vrct_gui/ui_managers/UiScalingManager.py b/vrct_gui/ui_managers/UiScalingManager.py
index ebac9bec..902951b5 100644
--- a/vrct_gui/ui_managers/UiScalingManager.py
+++ b/vrct_gui/ui_managers/UiScalingManager.py
@@ -6,6 +6,7 @@ class UiScalingManager():
         self.SCALING_FLOAT = max(scaling_float, 0.4)
         self.main = SimpleNamespace()
         self.config_window = SimpleNamespace()
+        self.modal_window = SimpleNamespace()
 
         self._calculatedUiSizes()
 
@@ -96,7 +97,7 @@ class UiScalingManager():
         self.main.MINIMIZE_SIDEBAR_BUTTON_ICON_SIZE_Y = self._calculateUiSize(26)
 
 
-
+        self.modal_window.TEXT_FONT_SIZE = self._calculateUiSize(20)
 
         # Top bar common
         self.config_window.TOP_BAR__HEIGHT = self._calculateUiSize(40)
diff --git a/vrct_gui/vrct_gui.py b/vrct_gui/vrct_gui.py
index 4913c64b..54705bb9 100644
--- a/vrct_gui/vrct_gui.py
+++ b/vrct_gui/vrct_gui.py
@@ -4,6 +4,7 @@ from customtkinter import CTk, CTkImage
 
 from  ._CreateSelectableLanguagesWindow import _CreateSelectableLanguagesWindow
 
+from ._CreateModalWindow import _CreateModalWindow
 from ._changeMainWindowWidgetsStatus import _changeMainWindowWidgetsStatus
 from ._changeConfigWindowWidgetsStatus import _changeConfigWindowWidgetsStatus
 from ._printToTextbox import _printToTextbox
@@ -17,6 +18,8 @@ from utils import callFunctionIfCallable
 class VRCT_GUI(CTk):
     def __init__(self):
         super().__init__()
+        self.adjusted_event=None
+
 
     def createGUI(self, settings, view_variable):
         self.settings = settings
@@ -41,6 +44,14 @@ class VRCT_GUI(CTk):
             view_variable=self._view_variable
         )
 
+        self.modal_window = _CreateModalWindow(
+            attach_window=self,
+            settings=self.settings.modal_window,
+            view_variable=self._view_variable
+        )
+
+
+
     def startMainLoop(self):
         self.mainloop()
 
@@ -52,9 +63,13 @@ class VRCT_GUI(CTk):
 
     def openConfigWindow(self, e):
         callFunctionIfCallable(self._view_variable.CALLBACK_OPEN_CONFIG_WINDOW)
+
+        self.adjustToMainWindowGeometry()
+        self.modal_window.deiconify()
+        self.bind("<Configure>", self.adjustToMainWindowGeometry)
+
         self.config_window.deiconify()
         self.config_window.focus_set()
-        self.config_window.focus()
         self.config_window.grab_set()
 
     def closeConfigWindow(self):
@@ -62,6 +77,9 @@ class VRCT_GUI(CTk):
         self.config_window.withdraw()
         self.config_window.grab_release()
 
+        self.modal_window.withdraw()
+        self.unbind("<Configure>")
+        self.adjusted_event=None
 
 
 
@@ -160,4 +178,21 @@ class VRCT_GUI(CTk):
         self.minimize_sidebar_button_container__for_closing.grid()
 
 
+    def adjustToMainWindowGeometry(self, e=None):
+        self.update_idletasks()
+        x_pos = self.winfo_rootx()
+        y_pos = self.winfo_rooty()
+        width_new = self.winfo_width()
+        height_new = self.winfo_height()
+        self.modal_window.geometry("{}x{}+{}+{}".format(width_new, height_new, x_pos, y_pos))
+
+        self.modal_window.lift()
+        if self.adjusted_event == str(e):
+            self.after(150, lambda: self.config_window.lift())
+        elif self.adjusted_event is None:
+            self.after(150, lambda: self.config_window.lift())
+
+        if e is not None:
+            self.adjusted_event=str(e)
+
 vrct_gui = VRCT_GUI()
\ No newline at end of file