Mikan Sakura is a cheerful and innocent 10-year-old girl who lives in the country with her grandfather. As she is preparing to save her school from being demolished, she remembers when she met her best friend, Hotaru, a year ago after the girl moved to the village. While the two constantly fight because of their opposing personalities, Mikan and Hotaru care deeply for each other, as close as sisters. Mikan discovers that Hotaruu is moving away to go to an elite school in Tokyo, which devastates Mikan, but they promise to stay in touch...