One of Keita's friends coaxes him into going to the pool with him and Mikazuki and inviting Ako and Riko. Suspicious of what they might be up to, Yūzuki decides to tail them. Whilst trying to hide from them in the bathroom, she is found by Ako and Riko who, mistaking her for a peeping tom, splash her with water. With her clothes soaked, Yūzuki borrows Keita's gym outfit. Later that night, Yūzuki becomes entranced by the smell of Keita's outfit and masturbates whilst wearing it and having sexual fantasies about Keita. She wakes up the next day to find that she had soaked his pants in the process.
Uno de los amigos de Keita, Toda, lo engatusa a ir a la piscina con él y Mikazuki e invitando a Ako y Riko por entregarle una revista erótica. Sospechoso de lo que podrían ser de hasta, yuzuki decide cola de ellos, a pesar de tener un dilema financiero (desde el ingreso a la piscina es costoso).
여름방학이 시작된 어느 날. 케이타는 토다의 제안으로 미카즈키, 아코, 리코와 함께 수영장에 가게 된다. 그 장면을 목격한 유즈키는 케이타와 쌍둥이 남매를 감시하기 위해 뒤를 쫓는데….