Giyū Tomioka holds the position of Water Hashira in the Demon Slayer Corps, ranking among its highest combatants. He stands tall with a pale complexion, sharp blue eyes, and uneven black hair usually secured in a low ponytail. His standard attire consists of a dark-tinted Demon Slayer uniform, white leg-wrapped kyahan, and zōri sandals featuring dark blue straps. His defining garment is a haori divided into two distinct patterns: the right side solid red, inherited from his sister Tsutako Tomioka after she died shielding him from a demon, and the left side patterned with geometric green, orange, and yellow motifs, originally worn by his deceased childhood friend Sabito. This haori embodies his survivor's guilt and profound losses. Following the final battle against Muzan Kibutsuji, he loses his right arm, adopts shorter loose hair, and transitions to traditional kimono and hakama pants. Giyū maintains a stoic, reserved demeanor, often viewed as aloof or arrogant by fellow Hashira including Sanemi Shinazugawa and Obanai Iguro. His emotional detachment originates from survivor's guilt after Sabito perished protecting him during Final Selection while he lay incapacitated. He struggles with deep-seated inferiority, initially rejecting his Hashira title and avoiding group training due to perceived unworthiness. This complex drives his intolerance toward those he deems wasteful of their lives. Despite his hatred of demons, he pragmatically spares Nezuko Kamado upon witnessing her resistance to human blood and Tanjiro Kamado’s resolve. He violates the Demon Slayer Corps’ code to protect her, pledging seppuku should she harm a human—a decision reflecting impartial judgment over blind hatred. Though socially withdrawn and vocal about hating conversation, he displays fierce loyalty to allies, losing composure when Shinobu Kochō dies or when Akaza targets Tanjiro. His guilt resurfaces when believing Tanjiro perished in the Muzan battle, admitting he "always gets saved" by others. Post-war, he exhibits increased emotional openness, smiling at the Kamado siblings and Sanemi, indicating reconciled relationships. As a Hashira, Giyū ranks among the Corps' most formidable warriors. Trained by Sakonji Urokodaki, he mastered Water Breathing and developed its eleventh form, "Dead Calm," which nullifies attacks within a radius of calm. Against Upper Rank Three Akaza, he awakens his Demon Slayer Mark—a navy-blue, fluid pattern on his left cheek—enhancing his speed, precision, and endurance. During the Muzan confrontation, his Nichirin sword turns bright red after clashing with Sanemi’s blade, temporarily halting demonic regeneration. His capabilities include inhuman reflexes, demonstrated by seizing Nezuko from Tanjiro effortlessly and decapitating Lower Rank Five Rui mid-blink. He possesses exceptional stamina, battling Akaza despite severe injuries and contributing to Muzan’s defeat after losing an arm. His tactical intellect allows him to analyze adversaries like Akaza’s precision and advise stalling tactics against Muzan. When Tanjiro transforms into a demon, Giyū immediately engages him to protect others, balancing duty with personal bonds. Giyū’s past reveals a cheerful childhood with Sabito under Urokodaki’s mentorship, where both wore fox masks—his white with blue eyes. Tsutako’s death and Sabito’s sacrifice during Final Selection catalyzed his depressive stoicism. He preserves their memories through his haori and suppresses emotional expression to contain grief. His development culminates when Tanjiro persuades him to value his life as a legacy to the lost rather than penance. Post-war, he retires alongside Sanemi, achieving mutual respect. In spin-offs like Kimetsu Gakuen Monogatari, he appears as a strict physical education teacher. His favorite food is simmered salmon with daikon, and he avoids alcohol, contrasting with Tengen Uzui.