He's an humanoid black cat, having a star-shaped symbol in his forehead just like his grandfather, Kuroboshi, wearing a brown kimono and green pant. In the 18th volume of the manga, his kimono is black and his pant is blue.
He seems like a very friendly cat on the surface, he affectionately likes to linger around girls, sit on their laps and pay them compliments. Despite his pleasing personality, Kuroboshi III hides a secret shame: he is terrified of ghosts. Because of his terror of the supernatural, he has developed a preternatural ability to detect the presence of nearby phantoms, even ones that are able to hide from Rinne and Sakura. Of course, he runs away in terror or goes berserk causing a mess, as soon as he suspects one is lurking nearby.
As Kuroboshi wishes to retire soon, he and Tamako both ask Rinne to take on the task of training the child to follow his footsteps, for Kuroboshi feels uneasy to have Tamako train him. Rinne and Rokumon both try to help him overcome his fear, but the young cat simply cannot get beyond it and eventually goes to live and be trained at Tamako's house. He hardly makes any progress.
- Transformation: He can transform to kitten form.
- Sensing Spirits: He has an uncanny ability to sense even the most well hidden specter.
He would scratch Rinne on his face, taking offense anytime he calls her "Granny". He would nevertheless seek his help all the time.
He is fond of Tamako. They get along well.
He is quite fond of Sakura.
They have good relationship. He hopes to follow his grandfather's footsteps, although he can't form a contract with Tamako until he overcomes his phobia, meaning Kuroboshi can't retire yet, much to his dismay.
- “Yes, I’m really really scared of spirits” (はい、私、幽霊がこわくてこわくてたまりません) - Chapter 176
- His introduction after Kuroboshi resurfaces, is the following chapter in the manga, as Kuroboshi declared wishing to retire after getting out of the closet. While in the anime, he appears in the following season.