Kuroyo Yuzuru, a bit of a plain boy, is always together with his best friend from childhood, Shirotama Kotaro.
They thought they could stay together forever even after they entered middle school...
One day, something happens that changes their relationship drastically.

ちょっぴり地味な男子「黒曜結弦」は親友の幼馴染「白玉小太郎」といつも一緒。
中学生になってもずっと一緒にいられると思ったのに…。
ある日二人の関係を大きく変える出来事が起きる。