K9Kuro is a VTuber and streamer whose short voice lines are often clipped by fans for soundboards and edits. This pillow princess line spread through that clip culture, where a single teasing phrase gets reused as a reaction to lazy or passive play. The term pillow princess itself is older internet slang with a flirty meaning, which is why the clip works even without context. It remains popular in small creator communities because it is instantly understood, easy to time, and fits both gaming and chat based humour.