Coco is a young girl, owner and friend of the titular cat Kuro. Her age isn't stated, but she appears to be less than 10 years old. Coco is silly, naive, and curious as shown by her daily interactions with Kuro. The 2 of them live alone together in a mansion.

Spoiler

Coco suffers severe psychological trauma due to the death of her parents in a car accident. All memory of the incident and her parents existence was blocked out of Coco's memory. She unwillingly ignores things such as the door to her parents bedroom or the fact that Kuro is a monster. She also never received the shot that allows humans to see monsters, so she is unaware of those as well, and sometimes puts herself in danger because of it. After remembering what happened to her parents, she locks herself away in her mansion with Kuro and refuses to speak with anyone.