The chant comes from the Fate series, where the Roman emperor Nero Claudius is reimagined as a cheerful anime heroine with a love of Christmas. Her playful version of a festive song turned the repeated phrase padoru padoru into a seasonal catchphrase, and anime fans began sharing it in edits, compilations and reaction videos. It spread through YouTube and TikTok, where its short length made it easy to loop, and it now returns every December as a familiar joke for fans who recognise the character and the holiday reference.