Kuromitsu is a tall, elegant female member of the black cat tribe who serves as the contracted partner of the shinigami Matsugo. She has brown hair styled in a fashionable apple‑cut bob from which a pair of cat ears emerge, light purple eyes, and a fair complexion. Her typical attire is a Chinese‑style dress that accentuates her refined appearance, and she is often regarded as one of the more striking black cat assistants. Her personality is consistently polite, kind‑hearted, and attentive. She is devoted to watching over Matsugo, who otherwise has no friends, and she cheerfully supports his attempts at forming connections with others. As his contract black cat, she possesses the standard supernatural abilities of her kind: she can shift between a normal cat, a monstrous form meant to intimidate, and the human‑like guise she usually maintains, while also wielding powers capable of spreading curses and ill omens. She is considered highly skilled in these duties, though her nurturing nature leads her to channel that competence into bolstering Matsugo rather than drawing attention to herself. Throughout the third season she remains a steadfast and protective presence, offering both practical assistance in spirit‑related cases and the emotional encouragement that Matsugo sorely needs.