Izumi Sano

The guy that Mizuki Ashiya likes and an excellent high jumper. He finds out that Mizuki is a girl early in the series, but does not tell anyone else and actually becomes very protective of her secret. Before Mizuki came to Japan, Sano had been in an accident (he had tried to save his team captain from getting hit by a car, injuring his leg), causing him to quit high jumping for a while because he thought that he couldn't handle the pressure. But thanks to Mizuki's deal with her brother (Sano had to jump while her brother was in Japan, or Mizuki would have to come home), he is able to try again and was given a second chance to high jump. Sano falls in love with Mizuki, but cannot tell her because Mizuki thinks that if Sano found out her secret, she would have to leave.

(Source: Wikipedia)