This clip comes from the Nijisanji VTuber Kenmochi Toya, whose streams and fan edits popularised the running joke that he is allergic to saying boku, the casual Japanese first-person pronoun. Fans clipped the moment and shared it as a short reaction sound, with a second version circulating alongside the original, which helped it spread through VTuber fan communities and meme edits. It remains popular because the joke is simple, instantly recognisable to Nijisanji viewers, and easy to drop into short videos.