• English / United States: Gary Oak
• Japanese / Japan: オーキド・シゲル
• Japanese (Romanized) / Japan: Shigeru Ōkido
• Japanese (TL) / Japan: Shigeru Okido
• French / France: Regis Chen

Gary, the grandson of Oak and Ash's biggest rival during the early seasons, was first seen at Professor Samuel Oak's laboratory after receiving his starter Pokémon. Ash Ketchum had arrived late and was unable to see his rival's Pokémon choice. Gary has his own fan club with him that follows him around wherever he goes.

Kanto Pokémon League Tournament:

With 10 Gym Badges, Gary Oak took his confidence and slight arogance from his Pokémon journey so far into the Kanto Pokémon League and continued to torment Ash who had also made it into the Kanto Pokémon League. Gary's first battle was on the ice field which he won easily, keeping all of his Pokémon from being KO'ed in the process.

Round 4 - Grass Field - Vs Melissa

It down to the last Pokémon of both Gary and Melissa to see whom would proceed to the final 16 of the Kanto Pokémon League. Towards the end of the battle Gary's Nidoking faced off against Melissa's Golem and both Pokémon looked tired. Gary ordered his Nidoking to use a Horn Attack, but Golem anticipated the move and managed to grab onto the horn and maintained a firm grip on it. In the final move of the round Golem used Seismic Toss on Nidoking, smashing it into the rock arena. When the dust settled Nidoking had been eliminated and Gary had been knocked out of the tournament.

Gary fell to his knees from the shock of the defeat and did not decide to stay to the end of the tournament, instead he left the Indigo Plateau with his distraught cheerleaders.