One day in early summer. Yoshiko, the shy older sister, and Kana, the active younger sister, are following Sawada, a university student with long hair. He is the boy of Yoshiko's dreams. Kana is left alone with Sawada, who is looking for a notebook that fell into the river, and starts asking him questions. When she is left alone, Kana starts to ask Sawada about his notebook, which has fallen into the river, and Sawada is taken aback by Kana's frankness but joins in the conversation. When Kana approaches him to tell him about her sister's feelings, he becomes reluctant to leave her side. As they repeatedly argue, their hearts somehow grow closer.