Costume☆Paradise ~Cinderella Rhapsody~

A huge entertainment theme park "Cinderella" is build on an island in Tokyo Bay aimed to "fulfill all people's dreams". Hero is a medical college student who works here as a part-time employee. The hourly is sky high, but he is required to cosplay along with the girls. He overcomes embarrassment and starts to pay attention to the cute girls around him.

[From vndbreview]