Russian Mahjong Harashō!

Russian Mahjong Harashō! is a one-on-one mahjong game. The protagonist is a young man who loses to a mysterious old witch in a mahjong match and as a result is turned into a woman and sent into a strange castle. In order to regain his former self he has to defeat young female opponents in mahjong. The order of these opponents is dictated by the plot; there is no option to play against them separately. After certain winning conditions are met (usually after the girl loses a fixed amount of money) the opponent removes an article of her clothing, eventually resulting in naked erotic images and transition to the next opponent.