This is May's contest rival Shuu, or Drew in the English version. He uses a Roselia to challenge May in the first Pokemon Contest on Slateport City. He first debuted in the episode, "Now That's Flower Power!" in which he met and became May's rival.
Drew is a Pokemon Coordinator much like May, only with more experience. When they first met, a rivalry between the two was quickly formed. Together with his Roselia and Masquerain, he competes in the Pokemon Contests trying to earn his way to the top.
During the first two contests, Shuu gave May/Haruka three roses for "Beautifly." He shows off in front of her continously and mocks her endlessly. He gives her advices and complements her from time to time. He is much more experienced than May, already having three contest ribbons by the time she got her first one. Shuu has even managed to beat Ash/Satoshi in a Pokemon battle and insults the rest of the gang. He is seen in most contest episodes. Many viewers, through hints in the show, believe that he likes May. One includes when he gave May a rose.
May: I suppose this is for Beautifly right?
Shuu: Yeah... Something like that.