Futaba Yoshioka has encountered her first love again in high school, but he seems different from the boy she once knew. At the cultural festival, Futaba and Kou kiss by accident and then for real. Futaba is on top of the world until she sees Yui in Kou's arms...

A mysterious boy comes to Saku Fujigaya's rescue when she falls ill on a train, but he leaves before she can thank him. After this experience, Saku never ignores strangers in need of help to emulate the boy who helped her.