X Ray has a secret that no-one else knows, he has eyes that have X-ray vision.
With one eye he has regular X-ray to see through clothes but not underwear, the other eye can see through clothes and underwear.
But using both all he can see is their internal organs and even their skeleton if he focuses hard enough.

Wearing an eye patch with a special seal on one eye he gets by, but he's fed up of seeing everyone in their underwear.
Moving to a new school he meets a group of girls and one of them he recognises as an old childhood friend, seeing how much she has grown he Is tempted to take a look with his other eye.

However a certain mindreading ability exposes his secret, Sunset however sympathises with him but gets him to reveal his secret to her friends.
Thankfully they aren't offended about his ability and tell him if he is to use his other eye that he's only allowed to look at them.