The story begins with an anonymous protagonist—a timid, socially awkward Japanese man—suddenly whisked away to Muma Sekai, a neon-drenched demon realm ruled by succubi. This world is a grotesque parody of prosperity, featuring floating mountains, bioluminescent forests, and cities where skyscrapers morph into tentacled entities. The vibrant, Instagram-ready aesthetics mask a terrifying reality: Muma Sekai is a predator’s playground.