One day, Takeshi, a student who is a ronin, greets his mother's friend arrogantly, saying, "You're just an old lady." However, the person who shows up is a beautiful mature woman, Eriko. What's more, Eriko, who has a teaching license, says, "I feel bad just letting her stay," and offers to be Takeshi's private tutor... Her guidance helps him study, but he can't get her voluptuous body out of his head. When Takeshi sees Eriko, who has fallen asleep without realizing it, he can't help but reach for her crotch...