An investigation adventure in which the player, acting as an unnamed Japanese detective, is called to solve the murder of a bank executive by searching for clues, exploring different areas, interacting with characters, and solving item-based puzzles. The game, especially its Famicom version, was received positively in Japan, where it was an influential title that defined the visual novel genre, as well as inspiring future designers such as Hideo Kojima and paving the way for creator Yuji Horii to go on to make Dragon Quest series of role-playing games.

Kouzou Yamakawa, the president of the Loan and Savings Company, was found dead inside his mansion. A detective and his assistant arrive at the scene for further investigation. The player must resolve the mystery of a murder by searching for clues, interacting with characters, and solving item-based puzzles.