A sudden ray of light shines into his boring daily life. Yuta falls in love at first sight with his mother's beautiful best friend, Sayuki. Sayuki has come from the countryside to stay with him for a few days, and Yuta wants to somehow become friends with her. His shyness and lack of ability to speak prevents him from joining in on conversations, and in his frustration, he impulsively uses her underwear as a masturbation aid. By chance, Sayuki happens to bump into Yuta, and instead of getting angry, she kisses him...