Mayumi

A Japanese high-school student receives a letter from his sweetheart Mayumi, who has gone to study in a remote school as an exchange student. Something in the tone of the letter convinces the young man that Mayumi might be a trouble. He travels to her school, only to discover that Mayumi was kidnapped. Now it is up to him to investigate the school premises, talk to the personnel and other students, and rescue his beloved one.

[From Moby Games]