Gundham Tanaka enrolled at Hope's Peak Academy as the Ultimate Breeder, distinguished by his mastery in taming, breeding, and caring for animals. This expertise included propagating endangered species and operating a secured website documenting his breeding research, accessible exclusively to individuals he deemed worthy. He perpetually carried four hamsters—San-D, Jum-P, Maga-Z, and Cham-P—collectively called the Four Dark Devas of Destruction, frequently concealing them within his scarf. Territorial aggression from these hamsters caused repeated bites, prompting him to shield his left arm with bandages. Raised solely by his mother during childhood, her deficient cooking skills inadvertently forged his self-perception. He silently consumed her meals to spare her feelings, nurturing a conviction that his body bore a "fearsome curse" capable of harming others through touch. This belief crystallized into a defensive persona, compelling him to avoid physical contact, shun communal activities like folk dances, and invent pretexts to escape interaction. Metaphorical claims of being "the offspring of an angel and a devil" implied his father's absence. Gundham manifested an intensely theatrical and eccentric personality, routinely declaring himself the "Supreme Overlord of Ice" and casting mundane interactions in apocalyptic, supernatural narratives. He ascribed this conduct to chuunibyou—delusions of grandeur—serving as a shield for profound loneliness and social anxiety. Despite his aloof exterior, he harbored deep empathy, particularly for animals, lamenting livestock destined for slaughter and adhering to ethical breeding protocols. He avoided involvement with animals bound for human consumption, hinting at vegetarian tendencies. At Hope's Peak Academy, he gradually connected with peers, most notably Sonia Nevermind, who mirrored his speech and mannerisms. His devotion to his hamsters included appointing caretakers during his absences. In one critical incident, his Pomeranian ingested a drug-laced drink spilled by Nagito Komaeda, triggering colossal growth and rampage. Unaware of the full circumstances, Gundham reclaimed the pet post-recovery. Preceding The Tragedy, he joined classmates scouring for the missing Mikan Tsumiki amid Reserve Course protests. Later, he aided the infiltration of Junko Enoshima’s lair, remaining with Nekomaru Nidai to hold off attackers. Witnessing Chiaki Nanami’s execution in a fabricated trial activated brainwashing via Junko’s despair video, transforming him into Ultimate Despair. As a Remnant of Despair, he committed global atrocities, including grafting unspecified parts of Junko’s body onto himself. During *Danganronpa 2: Goodbye Despair*’s virtual killing game, Gundham dueled Nekomaru in Chapter 4 to prevent others from starving. He emerged the killer, but both survived due to Nekomaru’s cybernetic enhancements. Accepting execution with unwavering resolve, he smiled while entrusting his hamsters to Sonia. After the virtual world’s shutdown, he lapsed into a coma alongside fellow Remnants. He awakened in the Hope Arc, reuniting with former classmates to defend Makoto Naegi from attackers, signaling his liberation from despair.