Usagi: Yasei no Touhai, loosely translated to "Rabbit: Fighting Tiles of the Wild", is a riichi mahjong game developed by Warashi (along with Mahjong Kobo) and released by Taito for arcades (using PS1-based Taito G-NET hardware) exclusively in Japan in 2001.
Based on the 1996 mahjong manga of the same name, Yasei no Touhai puts players in two-on-two matches of a slightly-different variation of riichi mahjong. Each of the game's playable characters are part of a group of high school students known as "ZOO", who act as "pinch hitters" in the world of mahjong and have their own supernatural abilities (such as main protagonist "Usagi's" ability to sense tiles in his hand that can make an opponent win).
- The first one, released on June 27, 2002 under the title Usagi: Yasei no Touhai, is rebuilt with a new engine. Rather than an arcade mode, this version includes a dedicated story mode that chronicles part of the original manga from the beginning. Much of the arcade version's visuals and audio have been reworked.
- The second one, released on March 27, 2003 under the title Usagi: Yasei no Touhai - The Arcade, is a straight port of the arcade game.
Both ports were later bundled together as part of the Simple series on December 9, 2004, under the title Simple 2000 Series Ultimate Vol. 22: Stylish Mahjong - Usagi: Yasei no Touhai & Usagi: Yasei no Touhai The Arcade - Double Pack.
The game received two sequels: Usagi: Yasei no Touhai - Yamashiro Mahjong-hen and Usagi: Yasei no Touhai Online.
- Shun "Usagi" Takeda - Automatically detects which tile in his hand can be used by another player to win.
- Ai "Yukihyou" Yamaguchi
- Kozue "Neko" Yamane
- Yuko "Kitsune" Kato
- Takashi "Chamois" Takizawa
- Akira "Jackal" Kusaka
- Akihisa "Saru" Sasaki
- Kengo "Chapman" Baba
- Iwao "Enchou" Kazama - Hidden opponent/partner in the Arcade version.