One time I was in line for some sort of merch drop and I didn’t know the Japanese word for Keychain so I did my best mangling Japanese words. I came up with “kagikazari” (key decoration) and the person behind the desk takes a moment before saying “kii horuda?” (Key Holder)
lol I was visiting my English friend who was living in Japan, and we were at a museum in Fukuoka and the guide asked where I was from and I said "nyuujiirando" and my friend, aghast, says that's not how you say that and the guide immediately says in delight "NYUUJIIRANDO!!"