Incineroar is the partner Pokémon of Kukui since he was a child and is Kukui's main partner under his Masked Royal persona. It shares much of Kukui's mannerisms and is an incredibly tough Pokémon in battle. It has often had to face up against up to three challengers at once. It knows the moves Bulk Up, Darkest Lariat, Throat Chop and Cross Chop. Using the Incinium Z, it can also call upon what is often used as its finished in Battle Royals, the Z-Move Malicious Moonsault. It has developed a rivalry with Ash's Torracat.

Professor Kukui has used his Braviary to help ward off various Pokémon and Team Rocket members. It's a powerful Pokémon with the moves Brave Bird and Rock Slide, but it ended up losing in battle to Gozu's Mega Aggron. It was later used against Ash's Lycanroc & Rowlet during the exhibition match. It has the moves Rock Throw and Steel Wing

Professor Kukui called his Lucario to help after Guzzlord came through an Ultra Wormhole and attacked the Alola Pokémon League. It used Dragon Pulse to try and push Guzzlord back into an Ultra Wormhole but fell in battle

Professor Kukui called his Venusaur to battle against Ash's Rowlet in the Alola Pokémon League's Exhibition Match. Using its bulb it was able to catch and trap Ash's Rowlet. It eventually defeated Rowlet but fell to Ash's Torracat. It also has the move Solar Beam and Vine Whip

Professor Kukui called his Empoleon to battle against Ash's Pikachu in the Alola Pokémon League's Exhibition Match. It had previously been used for underwater research. Using its moves such as Drill Peck and Whirlpool, it defended against Ash's Pikachu's attacks but eventually fell to Melmetal

Litten was Kukui's partner Pokémon as a child. As he was an eager trainer, when Ash inadvertently travelled back in time, he asked Ash to show him how to use Inferno Overdrive, as he had a Firium z given to him and following that, he challenged Ash to a battle, not wanting Ash to hold back. As Kukui grew up, Litten evolved.