One day, Takeshi, the son of a ronin, arrogantly greets his mother's friend when he comes to stay and says, "I'm an aunt anyway." However, what appeared was Eriko, a beautiful mature woman of mysterious age. Moreover, Eriko, who holds a teaching profession license, offered to be a tutor of Takeshi, saying, "I'm sorry to just stay." Her guidance helps her study, but her lustrous body is stuck in her head. Takeshi, who saw Eriko who fell asleep before she knew it, couldn't stand it and unintentionally reached for her crotch ...