Ai Uehara and Chiharu Kusakabe's beloved senior Hoshino-senpai is graduating. She wants to study science at a school far away, but that means Ai and Chiharu won't see her anymore. Ai struggles with the reality of senpai leaving, while Chiharu battles with her own unrequited feelings When a bold underclassman interlopes, though, things might take an unexpected turn...