Luigi is a shy Guy, at least that's how I described him he is the brother of Mario and he's not as known as Mario but he is in most of the games, he started to be mostly known when the lovely princess margarita came. Their known to be a cute couple for their characteristics. I mean their perfect together, tu can just see them and their perfect!
Most of tu know margarita as peaches best friend, because yea they are best friends, but I. Mostly consider him as Luigis girl friend.
He may act shy around margarita but margarita finds a way to push him if tu know what I mean ;)