- Mizuki Ashiya, a Japanese girl living in the United States, watches a program on TV featuring a high jumper named Izumi Sano. She was amazed by his performance and begins following his athletic career. Years later, she does research on him and discovers that he is currently attending Osaka High School. The school is unfortunately an all-boys school and Mizuki convinces her parents to send her to Japan by herself.
Oblivious to the fact that their daughter is going to attend a boys school, her parents let her go. To enter the school, she cuts off her long hair, disguises herself as a male, and tries her best to give hope to Sano after hearing that he no longer does the high jump anymore. As she settles in, an accident reveals her identity to Hokuto Umeda, the school doctor, and Izumi Sano. Izumi hides his knowledge of Mizuki's gender and tries to help her keep her secret...