Yuki chooses to go out with Kazuya after being confessed to by both her middle school classmate Jun and her college senior Kazuya. Soon after, Kazuya rekindles his old flame with his ex-girlfriend, and Jun is always there to comfort the sad Yuki, but Yuki can't get over the senpai she has always been in love with, and maintains a complicated triangular relationship.In the first grade of elementary school, Kaori began to like her classmate Horiuchi, who lent her a pencil eraser, but her unrequited love never progressed because she wanted to get close to him too much, but Kaori never gave up, and followed Horiuchi's footsteps through high school and college, continuing a 13-year long unrequited love.