Rikako Muto is a teenage girl who has just moved with her mother from Tokyo to Kochi. She is introduced to her school through the class president, Yutaka Matsuno, who hence introduces her to his best friend, Taku Morisaki. Yutaka (who instantly fell for Rikako) talks to Rikako about all things of life, including his best friend.

A school holiday to Hawaii comes up on the calendar. Rikako requests to borrow money from Taku, as she has lost hers. However, something is suspicious when it turns out Rikako had defied recommended stances by the teachers to limit their money to traveller's cheques, and instead of requesting it in dollars, Rikako requests it in yen...