Jantei Monogatari is a mahjong game originally released on PC Engine CD in 1990 and ported to the Sega Mega Drive the following year. It is a hybrid visual novel and mahjong game, where the player has to defeat various opponents at mahjong to gather new clues and evidence.

It features a whodunnit mystery where a private investigator is called to a girls' school to investigate the disappearance of one of its pupils. She vanished shortly after playing a game of mahjong with three other students, and to gather more clues the protagonist has to interrogate and eventually best those students and others at mahjong to get ever closer to finding the missing girl.