Yūki Yoshino is a petite student at Tōtsuki Culinary Institute residing in the Polar Star Dormitory. She possesses vibrant amber-colored hair usually styled in two buns and teal-colored eyes, wearing the standard Tōtsuki uniform; her hair grows longer over time, and she dons a chef's uniform with black trimmings for cooking. Cheerful, energetic, and competitive, Yūki serves as the dorm's mood maker. She enjoys teasing others and gossiping, showing immediate fascination with romantic hints among peers. She habitually adds "-cchi" to favored individuals' names, like "Erina-cchi." Despite her generally innocent demeanor, she reacts strongly to challenges, readily showcasing her culinary skills. Deeply loyal to her friends, she prioritizes the cohesion of Polar Star's 92nd Generation residents, demonstrated when she slaps Sōma Yukihira to prevent his expulsion during a Shokugeki meant to protect Megumi Tadokoro, later expressing profound relief the group remains intact. Yūki is self-conscious about her body and becomes upset comparing herself to more developed peers. She forms close bonds with Ryōko Sakaki and Megumi, frequently seeking comfort from Ryōko when distressed. Her emotional sensitivity leads to frequent mood swings, shifting rapidly from worry to anger or sadness, though her enthusiasm quickly returns. Her involvement begins at the 92nd Orientation Ceremony, witnessing speeches by Director Senzaemon Nakiri and Sōma. She soon assists Sōma's integration into Polar Star, participating in his welcome party where she tastes his Revamped Mackerel Onigiri Chazuke and learns French techniques like *Poêlée*. During the Tōtsuki Friendship and Rapport Training Camp, Yūki faces rigorous challenges, including preparing 50 dinner meals after exhaustive daily tasks. She initially despairs over the lack of rest but perseveres. On the fourth day, she completes the Breakfast Buffet Challenge by serving 200 dishes within two hours. Her relief is palpable when all Polar Star residents survive, and she tearfully enjoys the concluding banquet. Yūki qualifies for the 43rd Tōtsuki Autumn Election, highlighting her specialty in wild game cuisine. She keeps ducks, rabbits, and other animals in her room, aiming to breed a distinct "Polar Star" variety. For the preliminary round, she prepares Duck Cutlet Wild Game Curry with oranges, earning praise for flavor and ingredient quality, though she does not advance. Her vibrant personality attracts positive attention, including an invitation to a judge's buffet. In subsequent events, including the BLUE tournament, she continues supporting her peers and maintaining her role as a unifying figure within Polar Star.