Sakaki Ryoko attends Totsuki Culinary Institute as part of the 92nd Generation and resides at Polar Star Dormitory. Hailing from the Sakaki family's well-established koji and fermented goods business, she specializes in fermentation techniques. This expertise allows her to skillfully employ ingredients like black koji and shio koji in her cooking. Within Polar Star Dormitory, she maintains a dedicated fermentation workshop for experiments and produces fermented rice juice consumed by the residents. She possesses long purple or fuchsia hair, initially reaching her waist, which she later cuts to a chin-length bob upon advancing to her second year. Her physical traits include a curvaceous figure, red or orange eyes, and a characteristically calm, sophisticated demeanor. Her personality reflects maturity and level-headedness, distinguishing her among the dorm's more eccentric residents. She frequently serves as a stabilizing influence, offering comfort and guidance, particularly to younger students such as Yoshino Yuki and Megumi Tadokoro, who view her as an older sister figure. She maintains positive relationships with all dorm members, engaging in serious discussions with individuals like Ibusaki Shun who value her input. Academically competent, she navigates the rigorous Totsuki Friendship and Rapport Training Camp without major difficulties, supporting fellow dorm members during stressful periods like Tadokoro Megumi and Yukihira Soma's potential expulsion threat. Her culinary skills earn her a place in the 43rd Annual Totsuki Autumn Election. During the preliminaries, she presents "Soy Natto Curry Rice," a dish utilizing fermentation to transform initially plain components into a flavor-rich experience that impresses judges. Though she does not advance beyond the preliminary round, she remains supportive of other participants. Later, she assists Yukihira Soma by teaching him fermentation methods to enhance Pacific saury for his Nori Bento during the Autumn Election finals. She joins the defense of Polar Star Dormitory during the conflict against Central and Azami Nakiri's administration, resulting in her temporary expulsion from Totsuki alongside other rebel students. Following the rebels' victory, she resumes her studies and dorm residency. Her central role within the dorm persists as a nurturing and reliable figure, often overseeing the well-being of other residents and maintaining the communal spirit. Her documented presence remains consistent beyond this, with minor physical changes noted.