St. Ruri Girls Academy is a private institution recognized for providing the highest quality personal to the financial, political and sports world, this year it is celebrating its 100th anniversary and so a memorial ceremony is scheduled for the next month. The Student Council President and second year student, Hinomiya Maika, is the granddaughter of current principal Sakurakouji Rentarou, however she keeps it a secret and only a few people know it.

Maika and her friends spent her busy and fulfilling days towards the memorial ceremony until a certain day, a sudden change came to their peaceful school days. The principal, Rentarou, suddenly fell ill, and so, a man named Tendou Motoya came to take the role of acting director. Maika was suspicious of him and when she looked it up, she discovered that Motoya had a grudge against Rentarou and now he had taken over the school to clear said grudge.

It was then that Maika asked her friends for help to regain the school. Those friends were, her childhood friends Nikaidou Rie and Iori Sara, the former Student Council President Tamaki Juri and the Student Council Advisor Yomogi Youko. Also, those people were the only ones in school that knew about Maika being the granddaughter of the principal. Maika knew that if Motoya knew that she was related to Rentarou it might turn out dangerous, so before it could happen, she secretly started collecting evidence to kick Motoya out of school, because he wasn´t appointed officially.

But alas, certain day Maika was discovered to be the Rentarou's granddaughter and then, she suffered a relentless torture at the hands of Motoya and his colleagues. Maika decided to hide her situation from her friends and prepare a counterattack without getting them involved. Then, could it be possible for Maika to regain the school as she receives the harsh torture every day or will she end being swallowed like that?