Yuki Sohma bears the curse of the Rat from the Chinese Zodiac, transforming into a rat when embraced by someone of the opposite sex or under extreme stress. He is the younger brother of Ayame Sohma; their childhood relationship was distant due to parental favoritism towards Yuki as the Rat. His parents treated him as a tool for gaining status and wealth, offering little genuine care.

Severe respiratory problems plagued his youth. His mother sold him to family head Akito Sohma because of his Rat status. Akito initially treated Yuki as a playmate but later subjected him to years of psychological and emotional abuse. Akito frequently locked him in a dark, windowless room while convincing him he was worthless, unloved, and hated by others, including his family and fellow Zodiac members like Kyo Sohma. This abuse caused deep-seated trauma, resulting in low self-esteem, feelings of isolation, and a fear of rejection.

At an annual Sohma banquet, Yuki encountered Kyo Sohma, the Cat spirit. Attracted by Kyo's "pretty orange hair," Yuki attempted friendship but faced immediate rejection upon revealing his identity as the Rat. Kyo's hatred, stemming from the Rat's role in the Zodiac legend, reinforced Yuki's belief he was unworthy of connection.

Yuki later moved into Shigure Sohma's house to escape the main estate. His life shifted when classmate Tohru Honda discovered the Sohma curse and began living with them. Initially believing he was in love with Tohru, drawn to her kindness, Yuki eventually realized he saw her as a maternal figure who provided the unconditional love and emotional support he lacked. This relationship helped him confront his inner struggles, giving him the courage to "open the lid" to his suppressed emotions.

At Kaibara High School, Yuki was idolized as "Prince Yuki" for his beauty, academic excellence, and calm demeanor, inspiring a dedicated fan club. Despite his popularity, he felt isolated and envied Kyo's ability to form genuine connections. Joining the student council, he rose to president, forming close friendships with Kakeru Manabe and developing a romantic relationship with treasurer Machi Kuragi. Machi shared similar parental trauma. Their bond deepened as Yuki learned to accommodate her needs, like deliberately disrupting perfection to ease her anxiety.

Yuki's development involved shedding his "Prince" facade. He transitioned from formal, Chinese-style clothing to looser, casual attire, symbolizing his liberation from the Sohma family's constraints. He confronted Akito, choosing forgiveness to free himself from past pain. His self-awareness grew, acknowledging his earlier tendency to blame others and his desire to become capable of mutual relationships.

In the sequel *Fruits Basket Another*, Yuki married Machi Kuragi and had a son, Mutsuki Sohma. He maintained a career while supporting Machi through familial estrangement. As a father, he fostered a warm, communicative home environment, contrasting sharply with his own upbringing.

Yuki was perceptive and reflective, with a rich inner monologue. He struggled with authenticity, initially masking his true self behind politeness and aloofness. His journey centered on overcoming self-imposed isolation and learning reciprocal relationships. Key traits included compassion, seen in his support for Kisa Sohma and Machi, and resilience, as he gradually replaced melancholy with a more open, relaxed demeanor. A notable quote encapsulates his growth: "I wish I could’ve lived my life without making any wrong turns. But that’s impossible. A path like that doesn’t exist. We fail. We trip. We get lost. We make mistakes. And little by little, one step at a time, we push forward. It’s all we can do."