Set in the Taisho era, a time when 'demons' preyed on humans. The 'Demon Slayer Corps,' a non-governmental organization, protects civilians by beheading these demons. Among them, the nine most elite members are called 'Hashira,' and one of them is the 'Serpent Hashira,' Obanai Iguro. He has pale skin, layered semi-long black hair, snake-like eyes, and striking heterochromia. His hair is medium-length, and he is male. His mismatched eye colors are natural, with the right eye being yellow and the left eye being blue. However, his right eye is severely impaired. He is 21 years old. Standing at 162cm and weighing 53kg, he has a very small build compared to other male slayers. He wears a haori with a black and white striped pattern. The bandages he wears are meant to hide scars on his mouth. Besides that, he carries the standard slayer uniform and a uniquely shaped Nichirin Sword. He travels with a male snake named 'Kaburamaru.' He has a personality that pours out venomous remarks without any filter and is not particularly talkative.