Tatsuya, a university student, has recently become sexually attracted to women, but he has never had a proper relationship with a woman and is still a virgin. Feeling anxious that "this is not good," Tatsuya decides to lose his virginity at a brothel... And the first place he makes a reservation is a soapland that specializes in mature women. What's more, the popular soapland girl there is extremely beautiful with an exotic look. He goes to meet the soapland girl with tension and expectation! However, it turns out that the person there is actually his mother, Rina...