Kubinashi is a Nukekubi yōkai of the Nura Clan, his head floating detached above his shoulders. He stands approximately 160–168 cm tall and weighs 62 kg. His features include blond hair with black undertones, amber or blue eyes, and a constant black scarf. He wears traditional Japanese attire: an olive-green kimono layered with a blue-green jacket, straw sandals, and bandages around his legs, with red strings visibly attached to his clothing for combat. Originally a human thief in the Edo period, Kubinashi stole to aid the impoverished. He frequented Yoshiwara, falling deeply for the oiran Shiragiku and befriending her attendant, Kino. When Shiragiku refused to betray his location to a former target and committed suicide, Kubinashi and his comrades attempted a rescue. They were captured and killed by yōkai, his resulting trauma transforming him into a vengeful spirit known as "The String Assassin of Hitachi Province," who hunted other yōkai. His path changed upon encountering Rihan Nura, the Second Head of the Nura Clan. After a confrontation where Rihan intended execution, Kejōrō intervened and pleaded for his life. Kubinashi exchanged sakazuki with Rihan, pledging allegiance to the clan. This bond redirected his loyalty towards protecting the Nura Clan, particularly Rihan’s son Rikuo, whom he mentored during childhood by teaching cat’s cradle. His personality evolved from ruthless and solitary to disciplined and protective, though he retained a stern demeanor and low alcohol tolerance, addressing Rikuo as "Rikuo-sama." Kubinashi’s primary abilities involve manipulating enchanted strings he weaves. These strings grow stronger when imbued with "fear" and tighten against resistance. Techniques include "Ayatori String Technique: Cat's Cradle, Spiral Blade," creating spiral traps to slice enemies; "Spider Chain," suspending foes by the neck; and "Slithering Blade," dismembering targets through entanglement. He also crafts string replicas for combat or diversion. Throughout key conflicts, Kubinashi serves as Rikuo's bodyguard. During the Shikoku Arc, he impersonates Rikuo to draw out enemies like Inugami, immobilizing them with his strings, and later battles Hari Onna. In the Kyōto Arc, he reverts to solitary vengeance against Hagoromo Gitsune’s forces, nearly dying against Ibaraki Dōji before allies rescue him, with Kejōrō intervening to realign him with the clan. In the Hyaku Monogatari Clan Arc, he defends Rihan’s widow Wakana from Tamasaburō, emphasizing her importance to the Nura legacy. His relationship with Kejōrō is pivotal, having known each other since their human lives, with mutual romantic feelings implied but unstated. Kubinashi deeply respected Rihan, viewing Wakana’s protection as upholding Rihan’s legacy. He harbors guilt over the deaths of his human comrades, Seisuke and Kichijirō, which fueled his initial hatred for yōkai. In the OVA "Gekitō Dai Futsal Taikai! Nuragumi W Cup!!," Kubinashi participates in a futsal tournament alongside other Nura Clan members.