The outfits and appearance of characters in Pokemon XD are fixed and designed by the developers. They are not customizable in any way.
However, there are other ways to have fun with the game:
* Try different trainers: You can choose from different trainer types when starting a new game, each with their own unique style and appearance.
* Explore the world: Pokemon XD has a vast and interesting world to explore, with many different locations and characters to meet.
* Collect Pokemon: The core gameplay revolves around catching and training Pokemon. There are hundreds of different Pokemon to collect, each with their own unique abilities and moves.
* Battle other trainers: You can challenge other trainers to battles, test your skills, and earn rewards.
While you can't change Jovi's clothing, there are still many ways to enjoy Pokemon XD: Gale of Darkness!