April Fools events

Like most music games, SEGA's music games also have April Fools events each year around April 1st.

In 2020, due to w:COVID-19, April Fools events for all games were postponed to mid-June.

maimai

• 2013: セガサターン起動音 (NOT [H.][Remix]), playable on development cabs in SEGA only
• 2014: Site changed to "The world of three kingdoms"; 犬日和。 sung by はっぴー (4/1 only) [1]
  • Revived in 2019 as 犬日和。(はっぴー歌唱Ver)
• 2015: 全世界共通リズム感テスト (4/1~4/7) [2]
  • Expert and Master charts revived in 2019
• 2016: Wonderland Wars オープニング (4/1~4/7) [3]
  • Revived in 2019
• 2017: Garakuta Doll Play ガラクタ総選挙, 犬日和。 宴 星 (3/31~4/6) [4]
  • GDP No.1 and 犬日和。 revived on 2017/06/22 (MURASAKi+ release date)
  • GDP No.2~No.5 Revived in 2019
• 2018: 疾走あんさんぶる 宴 協, ミラクル・ショッピング 宴 蛸 (4/1~4/8) [5]
  • Playable normally since 2018/05/08
• 2019: 怒槌～光吉猛修一部謎～ 宴 宴 plus aforementioned revivals as 宴 attribute charts (4/1~) [6] [7]
  • 怒槌～光吉猛修一部謎～ is part of a cross-game event called AnotherVisionへの挑戦, a collaboration with the university students' creator group w:ja:AnotherVision. Charts in all 3 games, as well as the background video in maimai, contain puzzles that need to be solved. After entering the answers to the puzzles on the website (now closed), serial codes for in-game items in all 3 games were given as rewards. In CHUNITHM and ONGEKI, this event was not considered part of the regular April Fools events, and 怒槌～光吉猛修一部謎～ was not revived in subsequent years.
• 2020: Site changed to "maimai でらっくす TSUKEMEN"; 六厘歌 (6/19~) [8] [9] [10]
• 2021: Site changed to "maimai でらっくす The Piano"; タケモトピアノCMソング [11]
  • 全世界共通リズム感テスト revived in Asia
• 2022: Announcement to celebrate the completion of "OMEGA OFFICE 大鳥居イノベイテッドタワー -[i]3-". 3 songs added [12]
• 2023: Site changed to "ぱちんこ maimai でらっくす"; 2 songs added [13]
• 2024: Site changed to "MMT type DX", with maimai transformed into a racing car. 2 songs added [14]
• 2025: Site changed to "maimai でらっくす SAFARI PARK", 2 songs added and 1 UTAGE chart revived [15] [16]

CHUNITHM

All April Fool WE charts were revived in subsequent years.

• 2016: Help me, あーりん！ (4/1~4/6) [17]
  • Playable as イロドリミドリ Crazy Set Track 3 outside of April Fools
• 2017: あねぺったん (3/31~4/5) [18]
• 2018: イロドリミドリ杯花映塚全一決定戦公式テーマソング『ウソテイ』 (4/1~4/4) [19]
• 2019: なるがちゃんなぎにいよいよえれー目にあわされる話 (4/1~4/10) [20]
• 2020: 【3Dサウンド】小野ちゃんが真夏のビーチでスイカを叩き割る話【イヤホン推奨】, conflict(斉唱) (6月18日(木)～7月15日(水)) [21], [22]
  • conflict(斉唱) was added in the announcement on June 17th
• 2021: 恋はりんりん☆あーりんベル [23]
• 2022:
  • Japan:
    • [24]
    • Site changed to "CHUNITHM OLD"
    • Songs from the last century added
    • Cranky writes a song in 12 hours - 4月1日でございました
  • Asia:
    • [25]
    • "ChuMai", a game combining CHUNITHM and maimai, was announced
    • 2 songs are absent compared to Japan
• 2023:
  • CHUNITHM MOON, 3 classical arrangements added
  • 4月1日でございました WORLD'S END
• 2024:
  • Yukkuri-themed event, 2 songs added [26]
  • IRODORIMIDORI FANTASY VII RPG playable on the Irodorimidori website; ラストバトル ～サシュウとの戦い～ added
• 2025:
  • Cat-themed event, site changed to "CHUNITHM MEW", 1 song and 1 WORLD'S END chart added
  • IRODORIMIDORI FANTASY VII International playable on the website

ONGEKI

• 2019: ☆あかねさまのおんげきせいふく☆ featuring the song オンゲキ全域★アカネサマ? [27], [28] (4/1 7：00~4/10 23：59)
• 2020: すずしまさんちの夜ごはん featuring the song ぱくぱく☆がーる [29], [30], [31] (6/11 7:00~8/12 23:59)
• 2021: 奏坂NET麻雀 OJ [32]
• 2022: ソフマップ ～高瀬梨緒スーパーウルトラグレイト写真集発売記念イベント～ - Rio Takase's photobook release event/collab with Sofmap [33]
• 2023: いちげき！ themed event
• 2024: パチスロ オンゲキエンジェル collab event with ツインエンジェル [34]
• 2025: 共鳴合体 オトゲリヲン event [35]