Nyanpasu originated as Renge Miyauchi's greeting in Non Non Biyori, a manga by Atto that became an anime series in 2013 about children living in a quiet rural town. The word itself is a playful invention, combining the Japanese onomatopoeia for a cat's meow with a friendly hello, and it quickly became Renge's most quoted line. Clips of the greeting spread through anime fan videos, reaction edits and soundboards, where its cuteness made it easy to reuse outside the show. It remains popular because it instantly signals the series and its gentle, innocent humour.