Mahjong Princess Go! Go!

In Mahjong Princess, the player controls the titular character, a teenage girl named Chiruru Kawai, who has only two passions in her life: mahjong and sex. Those two are also the reasons for her taking part in a mahjong championship, where she competes against the toughest (and prettiest) mahjong ladies. The defeated party agrees to have sex with the winner... on her conditions.

The player selects one of the available eight mahjong opponents, most of which (with one or perhaps two exceptions) are pretty girls. Each player starts with 25000 points. If Chiruru runs out of points, it's Game Over; a victory over the princess' opponent leads to an explicit sex scene.