She watches over Yuuri and often takes on the form of a black cat.
Nai's teleportation ability uses shadows as a catalyst, using the shadows as portals Nai is freely able to travel between them.
Nai often takes on the form of a black cat and follows Yuuri around. She has also been shown to transform parts of her body into a shadow-like form
- Nai's name literally means "nothing".
- Zettai Karen Children Chapter 186 Page 11