Toko Agatsuma is the great-granddaughter of Zenitsu Agatsuma and Nezuko Kamado. She is also the older sister of Yoshiteru Agatsuma. Toko bears a great resemblance to her ancestor, Nezuko Kamado, having the same waist-length black hair parted to the left side of her forehead, though her hair tips are much darker than her ancestor's and are closer to an actual red color than Nezuko's orange. She has round, pink eyes with prominent eyelashes and thin eyebrows. Toko wears her school's standard uniform, consisting of a light blue long-sleeved shirt, black skirt, black ribbon necktie, and white vest. She also sports her uniform's black knee-socks and brown loafers. Towards her brother, Toko shows great aggravation and animosity, often berating him for his antics and telling him off for not studying. At times, she resorts to physically attacking Yoshiteru, such as kicking his back or tugging on his ear. Touko's harsh and violent actions show that she cares deeply about her younger brother's academic success and wants to see him grow up to be a mature and responsible individual. Through her efforts, Yoshiteru was able to improve his grades and gain admission to high school. However, when Toko is with Kanata Kamado, she instantly loses her angry demeanor and instead becomes much more jubilant, especially if Kanata compliments her. She is still easily annoyed by her brother if he interrupts her and Kanata's activities. Toko's personality shows that she doesn't believe in "superstitious" things, such as Zenitsu's journal about their journey to fight back against the demon race.