Fly High!(2008)

Meru Tachibana, 12 years old. She's just returned back to Tokyo after 7 years of training with her father, who thought she was a boy! Now Meru is stronger than most guys, and she's doing her best to make sure that people don't find out, or else her chances of making friends is ruined! However, a group of eighth graders seem insistant on making that impossible, as they break the rules and pick on the weak. Will Meru be able to stop them as the new student council president without appearing to be a "Monster From Melt King" as her mother has warned?