"Can I bring my boyfriend over to our house next time?" Yuko had various thoughts after her only daughter Shiho confessed that she had a boyfriend. And on the day of her arrival, Yuko was relieved to see that Shiho's boyfriend Shunpei, who is a whole year older than her, seemed sincere at first sight... However, on his second visit, Shunpei, who had promised not to lay hands on Shiho until she came of age, was about to do something inappropriate. Yuko, seeing this, proposed a deal to Shunpei...