My name is Ryoichi. A 22-year-old college senior. One day, I suddenly found myself living together with my older sister-in-law, Arari, for 10 days alone. But actually, my relationship with Arari is bitter-sweet... During my school days, when we were in the same school and in the senior-junior relationship in the track team, I fell in love with Arari and confessed... only to be spectacularly rejected. Despite that... To think I would end up cohabiting with a woman I once loved... I absolutely can't stand it...!
