Fashionable Yuzu’s life goes from sweet to sour when the beautiful but stern Mei falls into her life.

Fashionable Yuzu imagined the first day at her new school she transferred to after her mother's remarriage a bit differently; she didn't know it'd be an ultra-strict and conservative girls' school. So instead of a sweet high-school romance, she butts heads with the stern student council president Mei - who turns out to be her new stepsister. Now, she has to learn that hate and attraction are often not that far apart.