NAMES
Japanese: Sonezaki Masaki
Masaki is a simple name to explain. In the Japanese versions of the games, a lot of characters have names that are plant-related puns. For example, Ookido refers to "orchid," Sakaki is a persimmon, Kasumi is baby's breath, and Takeshi is bamboo. Meanwhile, Masaki refers to the Japanese spindle, a type of thorny bush cultivated for its hard wood. (This wood is ideal for making spindles, items used to spin thread. Hence the name.) In a sense, this could be a reference to his status as an inventor, someone who spins ideas that tie the Pokémon world together.
Sonezaki is a bit harder to define. While it's not confirmed in canon, the name most likely refers to a specific theater district in Osaka. (Hence, Masaki is literally "the spindle of Osaka.") There's not much else that can be said about this part of his name, so if anyone has more information, feel free to drop a line.
English: Bill (McKenzie?)
Canonically, Bill's name is just Bill. He has no last name, and he only goes by a casual nickname. The name itself most likely comes from Bill Gates, former CEO of Microsoft, and it sets off a string of computer-related puns among all of the other NPCs involved in the creation or maintenance of the PC Storage and Retrieval System except Amanita.
It should be noted that Bill is his name in various other languages, hence why this section doesn't have that much information on other translations.
Several surnames have been proposed for Bill over the years. Some of these stem from his Japanese name (by either using his given or family name). Others stem from his various occupations (Microbyte, Lighthouse, you name it). At least one canon (Rebirth) gives him a rather interesting surname that stems from the in-fic plot (Etherford).
Then, there's McKenzie, which has a story behind it. Back in the early days of Pokémon World, the website run by Nintendo, the site had a full section of episode summaries. While the summaries themselves were accurate, a lot of them seemed to be written before characters were given official English names. So, they anglicized the Japanese names, resulting in things like Marcus for Mathis (Lt. Surge), Glen Island for Guren (Cinnabar)...
And McKenzie for Masaki.
The mistake lasted until around 2003, but by then, it was picked up by a small circle of fangirls (the original Masaki Fan Club) who gave it to Bill as his surname. To this day, a handful still use it as his surname, though it's by no means canon or even fully fanon.
French: Léo
Not much is known about this translation except that it means "lion." If you have any further information as to why Bill might have been given this name, feel free to send us something about it.
Do you know of any other names? Have something to add to this section? Feel free to send us a word about it!