Anata Ja Nai to
あなたじゃないと
A high school girl named Hisami, who has never had a boyfriend, develops a crush on Haru-kun during a school event. A misunderstanding leads her to start dating his friend, Narushi, while Haru-kun begins dating Hisami's friend, Izumi. One day, Izumi proposes that they all switch partners for a single day. Eager to spend time with Haru-kun, Hisami agrees and ends up being taken to a love hotel by him.