Nyanpasu began as the signature greeting of Renge Miyauchi in Non Non Biyori, the slice-of-life anime about schoolchildren in a small rural town. Renge uses the made-up, cat-inspired word instead of a standard hello, and its odd, memorable sound helped it stick with viewers long after individual episodes. As anime clips and soundboards spread online, the short greeting travelled beyond the show's fandom and became a shorthand for cute, innocent energy in edits and reaction videos, which is why creators still reach for it years later.