Puniru is a sentient slime that Kotaro Kawaii created as a kid. Nobody's quite sure how or why it actually came to life, but it did—and it's been pretty vocal about being the cutest thing around ever since.
Originally, Puniru looked like a blue penguin wearing a hat. But as Kotaro grew up and stopped paying as much attention to her, Puniru made a calculated decision: transform into a cute girl and remind him why she deserved his affection. The old penguin form still exists as a side bag she carries, which doubles as storage for the slime ingredients she needs whenever she wants to shift shapes.
Despite the girl appearance, Puniru has no actual gender—the whole cute form thing is purely strategic on her part.
Content compiled by AnimeList.moe from publicly available sources.
