The phrase nani simply means what in Japanese, and shocked anime reactions using it have circulated online for years, helped by the wider omae wa mou shindeiru meme and countless subtitled clips. This tiny voiced version takes that familiar reaction and makes it cuter and quicker, so it spread as a reusable soundboard clip rather than a scene tied to one episode. Editors keep returning to it because the meaning is clear even for viewers who do not speak Japanese, and the squeaky delivery works for pets, chibi characters and silly edits.