diff --git a/common_module.py b/common_module.py
index 276de44..6787ad5 100644
--- a/common_module.py
+++ b/common_module.py
@@ -45,9 +45,3 @@ class CommonModule:
 
         return trimmed_left[:cls.index_by_f2c (trimmed_left, length)]
 
-    @staticmethod
-    def rad_to_deg (
-            rad:    float) \
-    -> float:
-        return rad * 180 / CMath.PI
-
diff --git a/main.py b/main.py
index 23375a0..956fd5e 100644
--- a/main.py
+++ b/main.py
@@ -1,6 +1,7 @@
 # vim: nosmartindent autoindent
 
 import json
+import math
 import random
 import subprocess
 import sys
@@ -149,11 +150,13 @@ class Main:
 
             # 日の角度
             sun.compute (observer_with_time)
-            sun_alt: float = CommonModule.rad_to_deg (sun.alt)
+            sun_alt: float = math.degrees (sun.alt)
+            sun_az: float = math.degrees (sun.az)
 
             # 月の角度
             moon.compute (observer_with_time)
-            moon_alt: float = CommonModule.rad_to_deg (moon.alt)
+            moon_alt: float = math.degrees (moon.alt)
+            moon_az: float = math.degrees (moon.az)
 
             # 月齢
             new_moon_dt: datetime = ephem.localtime (
@@ -166,7 +169,7 @@ class Main:
             cls.draw_bg (screen, bg_day, bg_evening, bg_night, bg_grass,
                          kita, jojoko,
                          sunrise_start, sunrise_end, sunset_start, sunset_end,
-                         sun_alt, moon_alt, moon_days_old)
+                         sun_alt, sun_az, moon_alt, moon_az, moon_days_old)
 
             # 左上に時刻表示
             for i in range (4):
@@ -296,7 +299,8 @@ class Main:
                                      bg_grass, kita, jojoko,
                                      sunrise_start, sunrise_end,
                                      sunset_start, sunset_end,
-                                     sun_alt, moon_alt, moon_days_old)
+                                     sun_alt, sun_az, moon_alt, moon_az,
+                                     moon_days_old)
 
                         chat_item.author = {'name':     'ゴートうひとり' if goatoh_talking else '伊地知ニジカ',
                                             'id':       '',
@@ -334,7 +338,9 @@ class Main:
             sunset_start:       datetime,
             sunset_end:         datetime,
             sun_alt:            float,
+            sun_az:             float,
             moon_alt:           float,
+            moon_az:            float,
             moon_days_old:      float) \
     -> None:
         sunrise_centre: datetime = (
@@ -368,14 +374,14 @@ class Main:
 
         screen.blit (bg_evening, (0, 0))
 
-        if -10 <= moon_alt < 40:
+        if (moon_az < 180) and (-10 <= moon_alt < 40):
             y = ((CWindow.HEIGHT / 2 + 100)
                  - (CWindow.HEIGHT / 2 + 200) / 30 * moon_alt)
             screen.blit (jojoko, jojoko.get_rect (center = (400, y)))
 
             screen.blit (bg_grass, (0, 0))
 
-        if -10 <= sun_alt < 40:
+        if (sun_az < 180) and (-10 <= sun_alt < 40):
             y = ((CWindow.HEIGHT / 2 + 100)
                  - (CWindow.HEIGHT / 2 + 200) / 30 * sun_alt)
             screen.blit (kita, kita.get_rect (center = (400, y)))