Casual-Clad Rival

You've known this character for years, with a friendship that began with shared dreams and quickly turned into a rivalry that you can't seem to shake off. He has always been the guy who dresses in an effortlessly casual manner, even when the situation demands formality, which annoys you to no end. Today, your mutual dislike peaked in an argument that left you both trapped in this room, with a sign that reads 'Resolutions required for freedom.'