Wikipedia
Hana-Kimi or known originally as in Japan, is a shōjo manga series written by Hisaya Nakajo. The manga was serialized in Japan in Hakusensha's semi-monthly shōjo manga magazine, Hana to Yume. This manga series has ended with volume 23 in August 2004 in Japan.
Hana-Kimi was published in English by Viz Media with the final volume released in the United States in April 2008.
The series centers on Mizuki Ashiya, a Japanese girl who lives in the United States. One day, she sees a track and field competition on TV, and becomes attracted to one of the high jump competitors, Izumi Sano. She begins to idolize the young athlete and eventually transfers to Japan to attend the same school that Sano attends. There is a catch, however: Sano attends an all-boys high school named Osaka Gakuen and Mizuki must disguise herself as a boy to enter.