"I wouldn't mind trying it with you, senpai." Hatsumi, a third-year substitute on the baseball team, flinches everytime at the slightly excessive skinship from Hinagi, a second-year regular. One day, however, Hatsumi witnesses Hinagi kissing another member of the club and begins to feel unsettled. A sensitive BL between a senior who is always an substitute and a junior who is a regular.