Sokosoko is a common Japanese word for something passable, and the clip survives on soundboards as a tiny reusable reaction with no confirmed source from any anime, game or creator. Meme editors and Japanese learners picked it up because it sounds funny and shrugging to non-speakers, while speakers enjoy its deadpan honesty. Its brevity makes it a quick verbal stamp for mid-tier moments in edits and streams. It keeps circulating because every creator occasionally needs the perfect meh.