Fuuka Reventon

Two girls living in an orphanage, Fuuka and Rinne, dream together of a better future.
However after a few years, Rinne is adopted and separated from Fuuka, pushing the latter into a streak of rebellious behavior.
One day, after being injured during a fight with a gang, Fuuka meets Einhart Stratos, a martial artist combatant at the Nakajima Gym. There she is offered employment as a sparring partner for the athletes in training.