diff --git a/src/locales/ja/arena-flyout.json b/src/locales/ja/arena-flyout.json
index 9e26dfeeb6e..1a9d2d6bb8c 100644
--- a/src/locales/ja/arena-flyout.json
+++ b/src/locales/ja/arena-flyout.json
@@ -1 +1,43 @@
-{}
\ No newline at end of file
+{
+  "activeBattleEffects": "バトル効果",
+  "player": "味方",
+  "neutral": "全員",
+  "enemy": "相手",
+
+  "sunny": "Sunny",
+  "rain": "Rain",
+  "sandstorm": "Sandstorm",
+  "hail": "Hail",
+  "snow": "Snow",
+  "fog": "Fog",
+  "heavyRain": "Heavy Rain",
+  "harshSun": "Harsh Sun",
+  "strongWinds": "Strong Winds",
+
+  "misty": "Misty Terrain",
+  "electric": "Electric Terrain",
+  "grassy": "Grassy Terrain",
+  "psychic": "Psychic Terrain",
+
+  "mudSport": "Mud Sport",
+  "waterSport": "Water Sport",
+  "spikes": "Spikes",
+  "toxicSpikes": "Toxic Spikes",
+  "mist": "Mist",
+  "futureSight": "Future Sight",
+  "doomDesire": "Doom Desire",
+  "wish": "Wish",
+  "stealthRock": "Stealth Rock",
+  "stickyWeb": "Sticky Web",
+  "trickRoom": "Trick Room",
+  "gravity": "Gravity",
+  "reflect": "Reflect",
+  "lightScreen": "Light Screen",
+  "auroraVeil": "Aurora Veil",
+  "quickGuard": "Quick Guard",
+  "wideGuard": "Wide Guard",
+  "matBlock": "Mat Block",
+  "craftyShield": "Crafty Shield",
+  "tailwind": "Tailwind",
+  "happyHour": "Happy Hour"
+}