

Spanish: pick your own name
Japanese: must use the Japanese-ified version of your name, eg Smith -> Sumisu, and people will usually refer to you by last name.
In retrospect, it was kinda strange to pick names in Spanish. It would be really strange / unacceptable to just pick a random Japanese name for yourself, and I’ve heard that it’s really rude to pick a name for yourself in American Sign Language. I wonder why it’s so widely accepted to do so for Spanish.






From article
It’s like a cultural thing. This still doesn’t really answer why it’s like that in the first place, but I think in general the reason it feels inappropriate to name yourself in another language is that it feels “cringe” for lack of a better word. Somebody picks a name that has all kinds of cultural and colloquial associations without understanding them at all.
That’s kinda my theory of cultural appropriation; it’s not wrong because of some deep ethical reason, but rather it’s just often uncool. People sending signals that they don’t understand themselves.