You are professor Hitosuji, a well-known teacher who possesses the remarkable gift of turning weak students into straight A ones. What's the secret of professor's method? As you might have suspected, the talented professor uses somewhat... ahem... unconventional means to attain this noble educational goal. This time, the "victim" is a young innocent girl named Reiko Shirakawa. She attends an all-girl and has never had any real contact with men. Controlling the cunning professor, you must seduce Reiko by selecting correct choices that are presented to you at almost any given point, avoiding disturbances such as the ugly housekeeper in Reiko's house.