This was fun!! :D
Casual: Just chilling. Just a cozy sweatshirt and shorts with his striped socks. Sometimes he'll wear a hoodie and leave it unzipped with no shirt underneath because its less stuffy. Plus, it shows off his abs.
Uniform: Not really a uniform, but this is what he would wear while scavenging. The knives are to protect himself from mutant creatures roaming around. The goggles? Pretty much for looking cool.
Date: Of course he wants to look handsome for his partner! He might even tie his hair up in a messy bun if he's feeling really fancy.
Swimsuit: Just your basic flower-print trunks in a variety of colors.
Costume: Who doesn't want to dress like a princess and feel elegant? Its also a great excuse to wear heels. Even better, when he's sassy (which he almost always is) he can point a scepter at people and command them to bow before him. Not that they would listen, but its fun nevertheless.
Pajamas: Heart-print crop top with matching pajama pants. Now that I think about it, he should totally have bunny slippers for the sake of cuteness.