Mahjong Sisters

Mahjong Sisters (麻雀シスターズ) is a 1986 adult strip mahjong arcade video game developed and published exclusively in Japan by Toaplan. Known as the studio's first and only entry into the "eroge" mahjong genre, the game departs from their legendary history of shoot 'em ups (like Truxton and Batsugun).

The game uses standard Japanese Riichi mahjong rules (Ari-Ari variant). Players start with a pool of points, and the objective is to deplete the opponent's points. Unlike many notoriously unfair arcade mahjong titles of the era, the computer AI in Mahjong Sisters does not cheat.