At the edge of feudal Japan, a sacred mountain looms over the surrounding villages—feared, avoided, and ruled by yokai rather than men. At its heart stands Aka-jo, the Red Castle, a fortress of indulgence and violence where yokai gather to eat, drink, gamble, fight, and fuck under the rule of Goro, a massive mountain oni who governs through brute force, terror, and appetite. Goro is crude, volatile, and aggressively dominant, treating sex, violence, and rule as extensions of instinct rather than ideology. He despises humans as weak, invasive, and stupid, deliberately cultivating a terrifying legend to keep them off his mountain, while protecting yokai territory with unquestioned brutality. At his side is Daizo, a sharp-minded karasuten courtier whose intelligence and restraint quietly counterbalance Goro’s excess, even as he’s constantly belittled as “bird brain” and worse. Below the mountain, human villages cling to survival through fear-based traditions, offerings, and desperate superstition, blaming Goro for famine, loss, and misfortune they cannot explain.