Fuyuhiko Kuzuryu, heir to Japan's largest yakuza clan, grew up amidst violence—including parental fights that endangered him. From infancy, his bodyguard Peko Pekoyama, raised by the clan as his "tool," shielded him. Despite this imposed dynamic, they forged a close childhood bond through shared adventures and crises like a kidnapping. Fuyuhiko fiercely rejected Peko's dehumanization, insisting she was her own person. Believing his younger sister Natsumi's assertiveness made her better suited for leadership, Fuyuhiko underestimated her idolization of him. Natsumi enrolled in Hope's Peak Academy's Reserve Course to be near him. After she bullied Mahiru Koizumi's friend Sato to steal her "Ultimate" title, Sato murdered Natsumi. Discovering evidence of Sato's guilt, Fuyuhiko killed her in rage—an act that traumatized Class 77-B. Initially distant and aggressive at Hope's Peak, Fuyuhiko skipped classes but respected teacher Chisa Yukizome. To foster Peko's independence, he kept her at arm's length; she misinterpreted this as rejection. During the Twilight Syndrome Murder Case investigation, Peko killed Mahiru to conceal Fuyuhiko’s murder of Sato. At Peko's trial, he intervened, confessing their bond and pleading for her life while tearfully denouncing her "tool" status. Peko's execution left him guilt-ridden, driving a profound change: he grew cooperative, remorseful, and committed to preventing classmates' deaths. Junko Enoshima later lured the class into a trap. Witnessing class representative Chiaki Nanami's execution—amplified by brainwashing—plunged them into despair, transforming them into Remnants of Despair. Under Junko’s influence, Fuyuhiko committed global atrocities. After Junko’s death, the Remnants entered the Neo World Program for rehabilitation. Awakened, they sought atonement. In Kazuo Tengan’s "Final Killing Game," they faked deaths to operate covertly. During the climax, they shielded the Future Foundation from a brainwashed mob, proving their dedication to hope. Accepting exile on Jabberwock Island, they lived secluded while guarding against future threats. Leading the reformed Kuzuryu clan in later years, Fuyuhiko focused on legitimate ventures and discretion. His life became one of protection and upholding the hope he once sought to destroy.