Mizuki, a Japanese-American track-and-field star, decides to transfer to a unique high school in Japan to be near her idol, the high jumper Izumi Sano. The catch? It's an all-boys school, and she must disguise herself as a boy. Coincidentally, Mizuki and Izumi end up not just as classmates but also as roommates. Mizuki faces the challenge of keeping her identity a secret in various settings, from the classroom to the locker room and even her own bedroom. As her classmates and the school nurse interact with the new transfer student, Mizuki's presence prompts them to reflect on their own feelings and identities.