The boy is a canon character from the Kanto region in the Pokémon game series.
The Kanto region is widely known for being the main setting for the first Pokémon games, Red and Green / Blue versions, along with later versions including Yellow, Let's Go, Pikachu!, and Let's Go, Eevee!
The games follows the main player (either Red for male, or Green for female), a young trainer from Pallet Town who explores the Kanto region, catching and training different Pokémon to battle it out against the region's Gym Trainers, earn their Gym Badges, and use them to battle the Elite Four, and eventually, the Champion of the Kanto region.
Along the way, Red/Green encounters a number of fellow Trainers who challenges him to a battle, more prominently his rival, Blue, who already defeated the Kanto Elite Four and briefly reigned as the Champion until his defeat. Also, Red/Green encounters the sinister Team Rocket, an organization led by the evil Giovanni to catch Pokémon and exploit them for profit. Among their gravest misdeeds includes the death of a Marowak, leaving its Cubone child orphaned and alone.
Once Red/Green defeats Blue in a challenge for the title of Champion, the player will discover a previously inaccessible cave near Cerulean City, and within it, the powerful Psychic Pokémon, Mewtwo!
Choose which scenario will apply:
Born Tiny: The male Pokémon Trainer is born tiny, as are all the other male characters in the Pokémon world except for the Pokémon themselves. To get around the region, the male Pokémon Trainer travels with his female counterpart and close friend and constantly encounters their former best friend and rival, who aims to be the Pokémon Champion of Kanto.
Psychic Shrinkage: After a Pokémon match with the Saffron City, the male Pokémon Trainer is shrunken down by Sabrina's psychic abilities, similar to the episode in the Pokémon anime. For her amusement, Sabrina plays with him like a little doll, or she teleports him to a female character who is none the wiser of his presence.
Kanto's Massive Meltdown: After an experiment goes haywire, the female characters, including Daisy Oak, the female Pokémon Trainers, Gym Leaders, and Elite Four members suddenly grow into giant size! See how the young male characters try to survive this massive outbreak of giantesses all over the Kanto Region!
Kanto's Pokémorph 'Pocalypse: Something in the world has gone wrong. The female Pokémon are becoming anthropomorphized! Not only that, they also seem to get bigger, and they are asserting their dominance all over the world! What happens when the male Pokémon Trainer from the Kanto-based games must survive in a world of Pokémorph giantesses?