Yuzu Aihara (voiced by Taketatsu Ayana) is a freshman in high school. She looks very fashionable, but she is actually a naive girl with no experience in love. Due to family reasons, Yuzu entered a girls' high school, which made Yuzu very dissatisfied, because the probability of her getting a boyfriend here is very small. On the first day of school, Yuzu met the student council president Mei (voiced by Tsuda Minami). Mei is a recognized beauty in the school. Whether it is appearance, grades or family background, she has left other peers far behind. Yuzu had a very bad influence on Mei because of a misunderstanding. What's worse, when she returned home, she found that Mei had become her sister, and the two were about to live under the same roof.