Satoshi "Sacha" Katsumoto

Sacha practiced a lot before having his first Pokémon. He wanted to make sure he had the perfect pose and line for whenever he'd catch his first Pokémon. He also thought of many nicknames for his partner Pokémon, Squirtle would be Zenibou. If it was a Bulbasaur, then Danesuke. A Charmander would have been Kagetarou. If his mother Hanako knew these names, she would probably question his naming sense and thwack him with a paper fan. Anyway, Sacha had never predicted the possibility that he'd end up with a Pikachu. “Uh, a name... Got it! Pikabou... Pikasuke... Pikatarou.” Pikachu had merely been looking away until now, but at this point turned his back completely. “I don't think he likes those names.” Professor Oak shrugged. Sacha continued calling out names as he thought of them. “Pikao. Pikata. Pikazaemon. Pikanosuke. Pikabee...” Pikachu liked none of them.

Sacha has a strong sense of justice, especially when it comes to Pokémon. If a Pokémon is in trouble, he will make every effort to help them, even if he has no prior connection to them. If they are the cause of trouble, he will stop them, and then try to understand them, with almost all such occasions being a case of the Pokémon, or their Trainers or friends, having a problem which can't be resolved normally. In those cases, he will selflessly volunteer to help them. Should the problem be caused by humans, such as Team Rocket, Pokémon thieves, hunters, or poachers, Sacha will resolve to do anything in his power to stop them.

Despite this, and previous dealings with villainous teams, Sacha has retained a remarkably optimistic and naive outlook. He is quick to praise and has an unshakable trust in both his Pokémon and his friends. Also, Sacha is determined to see the best in everybody unless he has a very good reason not to.

In the beginning of his journey, Sacha had a bit of an inferiority complex, as well as some form of personal pride, most likely stemming from his rivalry with Regis. As a result, he had some bad habits, such as shamelessly boasting of his skill if he were ever on a winning streak. Sacha used to complain about perfectly legal things during battles if he lost them. Fortunately, during his journey, Sacha has gotten over this particular character trait and became more accepting of criticism of his skill, though he still gets upset if his Pokémon are insulted or degraded.

He travels through Kanto, Johto, Hoenn, and Sinnoh with his best friend Sarha and meet new friends along the way, but he’s shocked when Sarha announces that she’s not going to follow him to his next destination, Unova. Instead, Sarha will go to the Ranger School of Acacia, in the region of Harmony. Sacha realizes he’s not going to see Sarha for a while and perhaps it’s time she knows his feelings for her have grown and, like a Pokémon, evolved into something else during their teen years. He decides not to, in the end, thinking it’d be too much of a burden for her to carry alone when she should focus on her Ranger Studies.

Sacha visits Unova with new friends but promises Sarha he’s going to show her his favorite places when she has graduated, and he does. In Nimbasa City, on February 2, he confessed his feelings to her.

Together again, the couple visits Kalos, return to Hoenn for a Mega Stone mission, and then go to Alola, where Sacha becomes the first Champion, at 18 years old.

At 19 years old, in Galar, Sacha competes in the Pokemon World Championship and defeats Leon, making Sacha the World's Greatest Pokémon Trainer.

After becoming World Champion, Sacha considered being a Ranger like his girlfriend, since he naturally cares about and helps Pokémon. He and Sarha thought about it and found out that being a Pokémon Master was just that: caring about Pokémon, understanding them. Not catching them all, not defeating them all. Loving them all. And Sacha is able to communicate with them and give them the help they need. He is a Pokémon Master. As such, he now travels the world with his friends and his Pokémon. Together, they meet old and new friends, and always give a hand to whoever needs it, Pokémon or human.