My character will be shy and sort of likes to keep to himself. He'll likely be a tad freaked out about who he's been paired with. 

Not sure if he'd do this for sport or not, but if I can't come up with some other excuse he will. His father is a famous inventor of magical artifacts, which is where he got his magic firing gun, so perhaps his opponent desires to study what he has so sort of forced this fight. Wouldn't want his magic gun stolen, though, as that's his thing. Perhaps it can teleport back to him by the power of convenience! And it's a magic gun so I can hand wave!