Obanai is a young man of short stature, pale skin complexion, and a lean, muscular build. He has straight-edged, raven-black hair of varying lengths, with the longest reaching down to his shoulders, while the shortest stop at his cheekbones, which he wears down with two shorter strands hanging between his eyes. His eyes are almond-shaped and tilted upwards on the far sides, and are uniquely colored due to Obanai possessing heterochromia. His right eye is yellow with a black pupil, while his left eye is teal, with the lower rim of the iris being a lighter shade. He is partially blind, barely being able to see out of his right eye. Obanai's mouth is usually hidden with white bandages over his lower face to hide his large facial scars, which were the result of his family horrifically cutting open his mouth to resemble that of a snake's gape.[5] Obanai wears the standard Demon Slayer Corps uniform, which is black in the manga and tinted a deep koamaru color in the anime. The uniform consists of a button-up jacket, a stand-up collar and long sleeves, adorned with gold buttons, a shirt pocket on the left breast, and the kanji for Destroy (滅めつ, Metsu?) engraved on the back. Beneath the jacket, he wears a white long-sleeved collared undershirt. The uniform is fastened at the waist with a white belt and paired with traditional tattsuke-hakama pants in the same koamaru hue. Over his uniform, Obanai wears his signature black-and-white vertically striped haori, with the hem and cuffs are striped horizontal ways rather than vertically, which covers his hands. For legwear, instead of the standard kyahan, Obanai wraps his lower legs in white bandages, giving the visual impression of traditional kyahan wraps. He also wears another set of white bandages around his lower face. His footwear consists of white zōri sandals with purple-blue straps, worn over koamaru-colored tabi socks to match the color tint of his uniform. He is also always seen with his white snake, Kaburamaru, wrapped around his shoulders. Obanai is a very harsh and strict individual who shows no concern for those who do not abide by the rules of the Demon Slayer Corps. His expectations for his fellow Demon Slayers are quite unrealistic, as he was seen berating Tengen Uzui for suffering heavy wounds against the lowest Upper Rank whom he called the "weakest" and telling him to "fight to the death" after Tengen insists on retiring. Tengen's retirement also highlights Obanai's devotion to the future of the Demon Slayer Corps. He does this often at others' expense such as when he tied up lower-ranked Demon Slayers and used them as obstacles during Hashira Training due to them commiting the "crimes" of being weak and annoying.[7]. He also sees the newer Demon Slayer recruits as weak and incapable of improvement, expressing extreme surprise when Tengen informs him that Tanjiro Kamado survived the battle with Daki and Gyutaro. Obanai has a rather prominent habit of pointing at people with his finger in an accusatory manner while berating or talking unfavorably about someone. Despite his merciless personality, there are two people he cares deeply about: Kagaya Ubuyashiki and Guest. He is married to Guest, and he often lets his affection shine through by sharing meals with her and giving her gifts. Obanai seems to let his overprotectiveness of Guest show at times, such as when he threatens Tanjiro for growing too close to her. It was implied that he chose to marry Guest because of the cheerful personality she retained despite going through very hellish training. Talking with her also made him forget all the strife and conflict he had encountered during his past, making him feel as if he were an ordinary young man. Like all the Hashira, Obanai has a great deal of respect for Kagaya. Obanai is noted to possess an immense sense of self-loathing due to the fact that he was born to a selfish and immoral clan who would mercilessly sacrifice even newborns to a demon for their own monetary gain. Obanai considers himself and his family so tainted, that years after the other members were killed, he still felt as if his family were digging their nails into his skin to make sure he couldn't go anywhere. His upbringing also seems to be the cause of his gynophobia since he was born into a family of only women who treated him like a tool. The trauma of his past can also be seen in the form of his facial bandages that he dons to cover the terrible scars he received. He is 21 years old, he is 5’3 3/4, and his favorite food is tororo konbu.