First generation of Pokemon at least, was conceived in both English and Japanese. They took pains to make sure the names in both languages were memorable to the children of their respective regions. Japanese names are rather standard in most cases or just literal descriptions.

English names are intentionally mostly a play on words. Ash, pulled from Satoshi. Ketchum is a reference to the English catchphrase “Gotta catch ‘em all!” Brock is the Rock Gym leader, Misty (as in rain) is the Water Gym leader, Jessie & James put together is Jesse James, famous outlaw and gang member like the Team Rocket (Rocket Gang in Japanese) duo.

The Pokemon names are usually portmandoes. Squirtle is squirting (water) turtle, Bulbasaur is a bulb (plant) dinosaur, and Charmander is a charring (fire) salamander.