SheZow!(2007)

A fifteen year-old boy, named Guy, accidentally becomes a superhero but the ring that gives him his superpowers was only meant to be worn by a woman. And now the ring is stuck on Guy's finger. So, whenever danger is near, the ring changes Guy into SheZow whether he likes it or not. And the only way for him to change back into his normal boy clothes is to eliminate the danger, so he has to be a "unique" superhero.