Mahjong Houtei Raoyui

The player assumes the role of a male student in a private high school, where he must compete against seven female opponents in the game of mahjong. The mahjong is always of the one-on-one variety. All the characters except the last one can be selected in any order from the main menu. If an opponent loses a mahjong match the player is rewarded with an erotic picture.

[From MobyGames]