Dejiko is the cat-eared heroine of Di Gi Charat, a Japanese anime and manga series, and nyo is the playful syllable she tacks onto the end of her sentences. Fans clipped that tiny verbal tic and shared it on soundboards and in anime edits, where it became shorthand for a cute, mischievous anime reaction. Like Tuturu, another short anime catchphrase, it survives because it is instantly recognisable even without context, easy to drop into memes, and short enough to work as a reaction, a punchline, or a character tag.