The phrase comes from Yu-Gi-Oh, the card-game anime in which Yugi challenges opponents to a duel, and the exaggerated du-du-du-duel delivery was popularised by the fan-made abridged parody series that turned the hero's catchphrase into a running joke. French-speaking fans adopted the same chant in translation, and it spread through short videos, streams and meme edits where a duel, contest or rivalry needed an instant, recognisable build-up. It endures because the rhythm alone signals a showdown, even for viewers who have never watched the original series.