Hello! 

In my game, there's a character that loves cosplaying. Everytime you meet him ingame, he'll be wearing different clothes related to animes/cartoons/games/movies/people.

He also dislikes pants and is always in his underwear and flip flops, which is one of the ways you can recognize him. His physical shape also changes everytime you meet him, as a part of a joke that is explained in game. 

This design choice will be a core part of the game's story and I wanted to know if there are any copyright issues. He'll never reveal which character he's cosplaying and it won't be super obvious. The player has to guess who he is (i don't know if that changes anything copyright related, but I thought I should mention it). Here's what 3 of his cosplays looks like (einsten, luffy and popeye):

Does anyone know if I'll have copyright issues with this?

Thank you!