Arisu Sakayanagi is the class representative of A-Class. Arisu is a petite teenage girl with lilac colored hair and violet eyes. She wears a black beret on her head with a gray ribbon connected to it and wears the standard school uniform. She often walks with a cane due to her health condition and she is quite short for her age when comparing to other classmates due to her congenital heart disease at birth. Many people in the school finds her cute but are afraid to approach her due to the power and dominion she wields. Arisu appears to possess a "go with the flow" attitude as she accepts most situations without protest or complaints. Although she does openly voice her dislike of boring situations after Kōhei Katsuragi (Arisu's classmate) spoke about the class scores. Unlike Katsuragi, who has a conservative stance, Arisu possesses an innovative outlook on things. Together, the pair effectively lead Class A through the school years. In the eyes of her schoolmates, she is considered to be someone who stands out from the rest and that no one has ever seen her lose her composure. Truthfully, she is just like any normal girl and the only one who was allowed and seen her act that way was Kiyotaka Ayanokōji. She enjoys situations she finds interesting as shown when she smiled at Kakeru Ryūen's declaration to rule the school or when she listened to the speech of Suzune Horikita. In the light novels, Arisu enjoys toying with people, as seen when she cryptically hinted that she knew Kiyotaka Ayanokōji, whereas he doesn't remember meeting her before. Later on, while being together with Honami Ichinose, she also appeared to be very confident and complacent after Teruhiko Yukimura of Ayanokōji Group boldly claimed that D-Class has a plan to overtake A-Class soon. She always carries an aura of imperturbability and seems like a wiseacre whenever anyone is in her presence. Although her soft tone could effortlessly make people feel comfortable around her. Additionally, although she has an easygoing personality, it was shown in the latter part of the series that she is easily provoked when being described based on her petite appearance (e.g. "Little Girl"), as she believes that it does not give her justice, due to her domineering qualities. She may come off as egotistical and arrogant towards onlookers, however this is also a frequent use of one of her tactics to establish control over the minds of those she chosen. She also holds grudges but doesn’t exhibit them on the outside. After Yamauchi made her fall and made a crude comment about her, she pretended that it didn’t affect her before plotting and executing his expulsion by pretending she was interested in him. She blatantly told Ichika Amasawa that she doesn’t view her as a threat and that she views her as a failure when compared to Kiyotaka. The latter successfully recognises that she is trying to agitate her and retaliated by accepting her challenge before walking away. In truth, Arisu finds her extremely dangerous and couldn’t afford to allow her to run free which prompted her to reign her in before she does something detrimental.