Genzō Shibata, a Japanese professional wrestler dubbed Kemono Mask, channels his ferocious athleticism into an unyielding mission: funding his dream pet shop through wrestling earnings. Clad in a canine mask and a muscular frame, his imposing presence often draws mistaken accusations of perversion. Transported to a fantasy realm by Princess Altena, he defiantly suplexes her upon hearing her plea to slaughter magical beasts, an act that etches her with the taunting moniker "Princess Buttocks." His obsession with animal traits—tails, ears, and fur—drives him to compulsively pet those bearing such features, though his fixation remains devoid of sexual intent.

Conflict resolution for Genzō means executing wrestling holds like the German suplex indiscriminately, whether subduing adversaries or pacifying creatures. He tames Cerberus packs and manticores with belly rubs rather than blades, earning the misconstrued title "Beast Killer," which he fiercely rejects. Despite his combat prowess, chronic financial woes plague him, as he hoards tamed beasts instead of profiting from them. Shigure, a wolf demi-human, begrudgingly manages his shop’s coffers, while dragon-girl Hanako and her vampire maid Carmilla endure his headlocks and playful aggression.

His rivalry with MAO, a former wrestling opponent turned Demon King, escalates when MAO allies with vampire princess Joanna. A curse from Carmilla strips his hair with each sneeze, adding absurdity to his struggles. Undeterred, Genzō launches a wrestling tournament in this new world, popularizing the sport while challenging norms. His interrupted 2016 match remains a pivotal relic of his past, yet his unorthodox ethos gradually reshapes societal views, fostering coexistence between humans and magical beasts—one suplex and belly rub at a time.