A子

A-ko, a red-haired girl who seems to be near invulnerable with superhuman speed and strength, is the heroine of the series and lives in Graviton City, Japan. A-ko is usually friendly and cheerful. She tries to lead a normal life, and spends a lot of time on clothes, a part-time job and romance in the sequels. However, she does have a fiery temper. She also has a large appetite and a tendency to oversleep on school days. She and C-ko are both transfer students to Graviton High, but wear their former school's sailor-style uniform for most of the film [From Wikipedia]