@Darkmint13 Yeah, British slang is varied and strange. Doesn't help that the dialect changes absurdly for such a small island. Start in one portion of England and travel for 30mins and you're in another spot where everyone talks different and you've past as least 5 different pronunciations of Bread.
So, slang has mutated a lot because of that.
Strange, but it could be that there simply wasn't a proper English word for the Japanese exclamation so the translator chose what they assumed to be the most appropriate.