Sailor Moon is originally a manga by Naoko Takeuchi that was later adapted into an anime. It is one of modern codifiers of the magical girl genre and a prime example thereof.
Sailor Moon is the heroine and head of a team of likeminded friends. They all can transform into magically enhanced disguised versions of themselves. In those disguises, closely resembling a mixture of sailor and school uniforms, they confront and defeat belligerent creatures draining the life out humans.