Sajin Komamura descends from a clan of anthropomorphic canines dwelling in Soul Society. He initially concealed his lupine features beneath a helmet and gloves, a consequence of societal prejudice. Acceptance into the Gotei 13 came through Captain-Commander Yamamoto Genryūsai, an act forging Komamura's unshakeable loyalty and defining his service as captain of the 7th Division. His formative bond with the blind Kaname Tōsen proved crucial, as Tōsen's lack of sight enabled acceptance without bias, rendering Tōsen's subsequent betrayal alongside Aizen Sousuke a deeply personal wound. Komamura's physical evolution paralleled his internal conflicts. Following Tōsen's treachery, he discarded his helmet permanently, signifying a resolve to face his identity openly. Amidst the Wandenreich invasion during the Thousand-Year Blood War, he temporarily adopted a humanoid form using his clan's forbidden Human Transformation Technique (人化の術, *Jinka no Jutsu*), gaining heightened power at the irreversible cost of his lifespan. This transformation enabled his Bankai, Kokujō Tengen Myō'ō: Dangai Jōe (黒縄天譴明王‧断鎧縄衣), to transcend physical damage by severing the link between himself and the construct—achieved through the ritual removal of his own heart. This sacrifice rendered his Bankai autonomous and immortal in battle. Upon the technique's expiration, Komamura reverted permanently to a non-anthropomorphic wolf, bereft of spiritual powers and reliant on care from his lieutenant, Tetsuzaemon Iba. His combat prowess centered on immense physical strength and his Zanpakutō, Tenken (天譴, "Heavenly Punishment"). Its Shikai summoned giant spectral limbs mirroring his actions, while his Bankai materialized a colossal armored samurai warrior replicating his sword strikes with devastating force. A critical flaw persisted: damage inflicted upon the giant reflected directly onto Komamura's body. The Dangai Jōe form nullified this vulnerability during the Wandenreich conflict, decisively overwhelming Sternritter Bambietta Basterbein by reflecting her explosive reishi projectiles back into her body. Komamura's personality blended fierce loyalty with introspection. His devotion to Yamamoto bordered on the absolute, fueling his pursuit of vengeance against Yhwach's forces after Yamamoto's death. Despite a gentle disposition—evidenced by keeping a dog named Goro and appreciating gifts like dog brushes—combat unleashed a ruthless, strategic focus. His clan's philosophy of isolation clashed with his own values; their elder criticized his involvement in Soul Society's wars, viewing worldly conflicts as irrelevant to their kind. This ideological divide underscored Komamura's choice to prioritize duty over heritage. Key narrative arcs tested his convictions. During the Soul Society arc, he confronted Kenpachi Zaraki and later Aizen and Tōsen, succumbing to Aizen's Kyōka Suigetsu. The Fake Karakura Town arc saw him defeat Arrancar Choe Neng Poww using his Bankai. His final arc culminated in the human transformation gambit against Bambietta, a pyrrhic victory fulfilling his oath to Yamamoto but costing his humanity. Post-war, his existence as an ordinary wolf represented both penance and peace, with Iba pledging steadfast support.