A 35-year-old high school teacher—and before he knew it, he had zero friends. The younger female teachers at work seem to take an odd interest in him, but their cold, disdainful stares are terrifying. Just when he thought he was completely alone, salvation comes from an unexpected source—Koume-chan, the most popular girl in his class. But instead of offering friendship, she says: "I'll be your teacher, sensei." …What does that even mean!?
