At the private Saginomiya Academy, where the children of the elite top one percent of society are gathered, an absolute rule exists: one must one-up others and rise to the top. This practice, known as mounting, is the ultimate method of social ranking. Rei Satou is the very definition of an average person and is certain to end up at the very bottom of the social class, destined to spend three years being tyrannized by his wealthy and powerful classmates. His only chance at survival is to find a way to move up to S-class.

Just as he resigns himself to his fate, a beautiful and unfamiliar girl named Senri Tsukinami suddenly appears before him. In an astonishing move, she tells him to kiss her and proposes a partnership. She declares, Be my boyfriend, so we can work our way up and mount ourselves on the pinnacle of happiness. Despite her being the most annoying girl he has ever met, Rei decides to join forces with her.

The series is a comedy and romance that focuses on the duo as they navigate the school's hierarchy. They engage in mounting battles, which are head-to-head competitions of wit and verbal sparring where the goal is to outdo and intellectually overwhelm opponents. The narrative follows their chaotic and humorous schemes as they aim to reach the top class of the academy, with Senri leading the charge with her forceful and condescending personality while the average but perhaps resourceful Rei struggles to keep up. The story began its serialization on August 18, 2022.