The phrase is Japanese for a blunt declaration that something is finished, romanised from hasudo owari da yo in the original title. Clips this short became popular on soundboards and in short-form edits because they work as instant punctuation, needing no setup or context to be understood by viewers familiar with anime reaction sounds. It circulates mainly as a reaction button and meme insert, shared between gaming, anime and fail videos where editors want a foreign-language line that still reads clearly from tone alone, even without translation.