An RP about character exploration and development set in modern day. 

The plot would be your characters learning how to embrace their true selves while working to protect the world from villains (who use their avatars for bad).

The main mechanic and gimmick (I'm not sure of a better term) would be that each character has an "avatar" that they can shift into to access a powered up form and their powers. Avatars represent the parts of their personalities that they're hiding/repressing for various reasons, think [url=https://en.wikipedia.org/wiki/Masking_(behavior)]masking [/url], but taken to the extreme. To access a character's avatar, they have to metaphorically unmask or something like that; I guess it only happens when they're truly ready to embrace themselves or something akin to that? I'm not really sure; you can just think of it as a Power Rangers morph for now.