In PLEASE TEACHER! Kei Kusanagi is actually older than he seems. A rare disorder left him in a coma for three years and stunted his growth. Now he lives as an 18-year-old in the body of a 15-year-old. His gorgeous teacher Mizuho Kazami also has a secret. She is actually an alien sent to Earth to study the strange ways of humans. Although Kei and Mizuho fall in love and get married they hide their secret from everyone else. Being both a school kid and a married man Kei finds himself in many humorous and strange scenarios. For example what is Kei supposed to do when a classmate falls for him?