Choso is a half-human, half-cursed spirit hybrid, the eldest of nine Death Painting Wombs created through experiments by the curse user Kenjaku (using the identity Noritoshi Kamo). Kenjaku impregnated a woman capable of bearing cursed spirit children and mixed his own blood into the pregnancy, becoming one of Choso's three "parents". Choso and his brothers were sealed as cursed objects for approximately 150 years before Mahito incarnated them into human bodies in the modern era. Initially, Choso allied with Kenjaku and Mahito's group, driven pragmatically by the desire to create a world where he could live peacefully with his younger brothers Eso and Kechizu. He harbored no inherent hatred toward humans or sorcerers. After Yuji Itadori and Nobara Kugisaki killed Eso and Kechizu, Choso vowed revenge against them, viewing Yuji as his family's murderer. During the Shibuya Incident, Choso participated in sealing Satoru Gojo but maintained distance. After Gojo's sealing, he pursued Yuji, cornering him in a bathroom for a decisive battle. Despite overpowering Yuji and preparing a killing blow, Choso experienced a sudden, vivid false memory of sharing a meal with Eso, Kechizu, and Yuji as brothers. This vision—potentially influenced by Sukuna—halted his attack. Choso deduced Yuji must be a blood relative, as both were Kenjaku's creations (Kenjaku also orchestrated Yuji's birth as Sukuna's vessel). This transformed Choso's allegiance; he renounced his vendetta and devoted himself to protecting Yuji as his "younger brother". Choso's character centers on unwavering familial loyalty. As the self-proclaimed "oldest brother of ten siblings," he believes his role is to walk ahead, serving as his brothers' protector and moral guide. This conviction drove his actions after joining Yuji: he forgave Yuji for Eso and Kechizu's deaths, viewing their conflict as a tragic misunderstanding. He later expressed deep regret for previously encouraging his brothers to "live as curses," believing this choice denied them a future where all four could fight together. In combat, Choso is a Special Grade threat wielding the inherited cursed technique **Blood Manipulation**. His mastery surpasses the Kamo clan's current head, honed over 150 years of conscious existence as a cursed object. Key techniques include compressing blood for advanced attacks (**Convergence**), firing high-velocity blood projectiles (**Piercing Blood**), detonating compressed blood for area damage (**Supernova**), enhancing physical capabilities via blood flow acceleration (**Flowing Red Scale**), and manifesting blood wings to fire homing projectiles as a tribute to Eso (**Wing King**). His blood is inherently poisonous, weakening opponents on contact. His Death Painting physiology grants the **Blood Connection**, allowing him to sense his siblings' deaths or near-death states. This triggered his awareness of Yuji's lineage and later informed him of Yuji's critical condition during their fight. Choso's tactical intellect enables creative adaptation of techniques, such as using environmental factors like wounds as blood sources or combining moves like **Blood Meteorite** with close-quarters combat. He defeated Naoya Zenin by exploiting Naoya's overconfidence and countering his speed-based technique with strategic blood attacks. He also confronted Kenjaku directly to avenge his family, nearly succeeding by forcing Kenjaku to reveal hidden abilities. His development includes embracing humanity after a pivotal conversation with Yuki Tsukumo, who advised him to "die as a curse to live as a human" alongside Yuji. Following her death, he honored her legacy by sharing her research with Yuji. He later trained Yuji in Blood Manipulation fundamentals, reinforcing their bond. Choso ultimately sacrificed himself during a battle against Sukuna to protect Yuji.