>>9064762It's a japanese loanword like (w)otaku, sayonara, banzai, teriyaki, katana, yuri, yaoi, hentai, etc. This is how language evolves. Words get borrowed to simplify concepts that would be more difficult to describe in one's native tongue. Japan does the same thing with English. They even made an alphabet for it called "katakana."
Like it or not, oshi has settled into being commonly accepted slang for your favorite vtuber in general. Waifu would be used in place of oshi's original connotations, as waifu always implied having an actual emotional affection/obsession for the character.
Linguistics!
