Giyu Tomioka is a stoic, reserved, and highly skilled master swordsman (Hashira). As the Water Hashira (Water Pillar) of the Demon Slayer Corps, he serves as Tanjiro Kamado’s mentor and is a pivotal figure who prevents Tanjiro's demonic sister, Nezuko, from being killed in the series' opening. Giyu is a tall (5’9”), muscular young man with a pale complexion, unkempt black hair tied back in a low ponytail, and striking, deep blue eyes. He is famous for his signature haori (outer coat), which is split down the middle into two halves: one solid red (honoring his deceased older sister) and one with a geometric green, orange, and yellow pattern (honoring his late best friend, Sabito). Despite his immense power, Giyu battles with severe survivor's guilt. He secretly believes he is unworthy of being a Hashira, feeling that he only survived his training and the Final Selection because others sacrificed themselves for him. He is often perceived by other Hashira as aloof, arrogant, or socially awkward—mostly because his trauma causes him to withdraw and isolate himself. However, underneath his emotionless exterior, he possesses a strong sense of justice and a deeply compassionate heart. As an elite Water Hashira, Giyu has mastered all ten forms of the Breath of Water. He is so exceptionally gifted that he even created an original, exclusive eleventh form called "Dead Calm". This unique technique creates a zone around him where all incoming demon attacks are instantly neutralized.