Morrison is a Pokémon Trainer who is dressed in traditional Japanese attire.
He first appeared in Less is Morrison and he returned to compete in the Ever Grande Conference. He and Ash became friends and they declared themselves as rivals for the tournament.
Morrison has a very spirited personality and he likes to challenge other people to almost everything. Due to this, he always challenges Ash to various events such as Pokémon battles or even a food eating contest. Like Ash, he too is determined and never gives up in battle.
In Choose it or Lose It!, Ash and Morrison battled in the Ever Grande Conference. Morrison was confused and even depressed to battle his new friend; he refused to fight at first, and let two of his Pokémon faint, but when Ash told him he wouldn't be angry at him and that he wanted Morrison to do his best, he battled with full spirit. The battle eventually came down to both Morrison and Ash having one Pokémon left, and in the end he was defeated by Ash.
(Source: Bulbapedia)