Haruna Aizawa is compelled to transfer from the prestigious K Academy following a corruption scandal involving her politician father. She had believed she shared strong bonds with her former friends, yet they severed ties with her all too readily once the news broke. Consequently, Haruna approaches her new high school and future classmates with skepticism. She views school life as akin to a monkey mountain, where members of the same gang constantly fight and reconcile, establishing a hierarchy. Therefore, she harbors no expectations of integrating into the school's existing social structure. Masaru "Macharu" Yamashita is one of Haruna's new classmates, and his appearance is reminiscent of a baby monkey. He interacts with Haruna with remarkable sincerity, and despite her reservations, she begins to open up to him. One day, she mistakenly compares their class to a pack of wild monkeys in his presence, prompting him to question her position within that dynamic. Is she observing from the top? Or is she an outsider looking on? Spending time with Macharu forces Haruna to confront her vulnerabilities and wonder why she lowers her guard only for him—could this be love?