Maiku Kamishiro's past has always been somewhat of a mystery to him. The only clue he has to who his family might be is an old photograph showing two young children, a boy and a girl, playing in a small pool outside of a blue house. In an attempt to find his family, he moves to this blue house and begins working as a programmer. He's living a comfortable life until the day two very different girls show up at his door, both in possession of the same photograph, and both claiming to be his twin. With no way to prove who is a relative and who is a stranger, Maiku allows both girls to move in with him until they know for sure. 

(Source: ANN)

Pokemon are peculiar creatures with a vast array of different abilities and appearances; many people, known as Pokemon trainers, capture and train them, often with the intent of battling others. Young Satoshi has not only dreamed of becoming a Pokemon trainer but also a "Pokemon Master," and on the arrival of his 10th birthday, he finally has a chance to make that dream a reality. Unfortunately for him, all three Pokemon available to beginning trainers have already been claimed and only Pikachu, a rebellious Electric type Pokemon, remains. However, this chance encounter would mark the start of a lifelong friendship and an epic adventure! Setting off on a journey to become the very best, Satoshi and Pikachu travel across beautiful, sprawling regions with their friends Kasumi, a Water type trainer, and Takeshi, a Rock type trainer. But danger lurks around every corner. The infamous Team Rocket is always nearby, seeking to steal powerful Pokemon through nefarious schemes. It'll be up to Satoshi and his friends to thwart their efforts as he also strives to earn the eight Pokemon Gym Badges he'll need to challenge the Pokemon League, and eventually claim the title of Pokemon Master. [Written by MAL Rewrite]

After participating in the Johto League, Satoshi decides to begin anew in yet another journey; this time by himself and Pikachu, in the land of Houen. Though he isn't alone for long, as 10-year-old Haruka (whom dislikes Pokemon, but just wants to come along to see the world) travels with him after Pikachu destroys her bicycle. Satoshi also meets up with his old companion, Takeshi, and Haruka's younger brother, Masato. Together, they travel along in Houen, battling Gym Leaders, entering Contests, and other events on the way to the Houen League. (Source: ANN, edited)

Following the end of Satoshi's Hoenn journey, he travels to the Sinnoh region for his next adventure en route to becoming a Pokémon Master. Immediately upon arrival, Team Rocket makes another attempt to snatch Pikachu, only for it to fail once again. However, Pikachu has fallen deep into a forest and it's up to Satoshi to find him! Along the way, he reunites with Takeshi—a Pokémon breeder with whom he has traveled through many regions—and meets his soon-to-be rival, Shinji, a power-hungry trainer who cares little for his Pokémons' feelings. Still in search for Pikachu, Satoshi notices a powerful electric attack in the distance and heads toward it to find Pikachu with Team Rocket and Hikari—a novice trainer aiming to be the top Pokémon coordinator. After foiling Team Rocket's plans, Satoshi reunites with Pikachu and Hikari joins the group. And thus, Ash and his friends begin their journey through the exciting land of Sinnoh. [Written by MAL Rewrite]