Max is the brother of May in the anime. He has not yet received a Pokémon because he is underage, but is a part of some adventures with Ash, Brock and May. He also pulls Brock's ear when he is talking to a pretty women, similar to the way Misty did in Kanto and Johto, and the way his Croagunk poison jabs him in Sinnoh.
Max is a genius in the theory of Pokémon training, but he was too young to receive a Pokémon when he first appeared.
Both May and Max are the children of Norman, the Gym Leader of Petalburg City and his wife Caroline. The two have a very close relationship. They often get upset with each other, but when they are in dangerous situations they try to protect each other, especially May. She sometimes gets annoyed with Max because he knows a lot about Pokémon and she is additionally annoyed by not knowing the basics of training or Pokémon. He decided to travel with Ash and May to see even more Pokémon.
When Ash arrives at the gym without May in Petalburg City, he was met by little Max who was surprised to meet a trainer who he had watched on television only weeks ago, through participation in the Johto League Silver Conference. But he also mocked him for losing in the quarterfinals of the tournament. He also criticized the PokémonMay chose, Torchic, saying he would have chosen a Treecko.
Max's PokéNav charges, which belongs to May. In the following episodes, when accompanying Brock, Max makes a habit of pulling Brock's ear when he sees and talks to a pretty girl, as did Misty in early seasons, since Max made Brock suddenly halt his romantic advances.
In the movie Jirachi: Wish Maker, Jirachi partnered with Max, becoming his first Pokémon. In Do I hear a Ralts, Max rescued a Ralts that was hurt and took the job of returning it back to its family, Gardivour and Kirlia.
In the Pokemon: Diamond and Pearl series, there are cameo appearances of Max and his parents watching May compete in the Wallace Cup, and also appears in a photo in the Pokémon Diamond and Pearl Special Episode 2.
As Max has not become an official Pokémon Trainer, he does not own any Pokémon,but he has befriended some wild Pokémon and borrow some from Ash and the others Occasionally.
Max befriended a Poochyena and, although his three brothers who were born at the same time, Poochyena was unable to evolve like them. The only move it knew was tackle so Max attempted to teach it Bite. After a battle with Team Rocket, after using Bite, it evolved.
In the episode "Do I hear a Ralts?", our heroes encounter a Ralts that is really sick and Max took him to a Pokémon Center. At the end of the chapter, Ralts went back to the woods and saw its family members, Kirlia and Gardevoir. Max promises Ralts that he'll come back when he's a Pokemon Trainer.
While Max was walking around in a building with Ash, May and Brock, he accidentally stepped on Poliwag's tail and it immediately came out. After Max apologized to the Tadpole Pokémon, it was revealed that it belonged to the Pokémon Trainer's School in Hoenn. Later on, Max was given Poliwag as he was choosing a Poké Ball for the training arena. It was narrowly defeated by Tommy's Magby as Team Rocket interrupted the match as they were stealing Poké Balls from the Deposit Room. While Poliwag distracted Team Rocket, Magby's Flamethrower burned the Wurmple mecha Team Rocket was on and they were blasted off.