Kaname and Riho have been dating for two years. Riho is head over heels in love with Kaname, who is the leading type, but recently she has been a little dissatisfied with their sex life... Even during sex, he is always the one taking the lead, and when she tries to approach him, she is easily brushed off. Then, one day, Kaname injures his dominant hand, and she thinks that her chance has come...!