Birthday: unknown; however, judging by when the Niji breed, you can imagine he was born in spring.
Age: unknown
Height: 157 cm (5'1")
Blood type: unknown
Likes: playing hide and seek with the sheep, basking in the sun
Dislikes: Studying and lessons with Tsukumo
Liked foods: Mochi Onigiri
Dislike foods: lamb (because of the Circus sheep...)
Hair color: white and purple
Eye color: red

Compared to before, his vocabulary has increased, but because he still uses it the wrong way, he is scolded by Gareki very often. He appears to be timid at first glance, but surprisingly his actions are often bold.

Nai's name means "nothing, not existing."

(Source: extra pages from chapter 18)