In Kyoto during the Heian period, a bizarre incident unfolds as a mysterious group called the Onimen Party terrorizes the populace with horrifying sorcery. In the year 2480, the government establishes a new law enforcement unit, the "Time-Space Force," tasked with crossing eras to eliminate criminal fugitives. Among them, the strongest swordsman, Hayami, is dispatched to the Heian era to capture the escaped time-space criminal Onimen Saisei. As Hayami investigates Kyoto in pursuit of his target, he discovers the city has become a den of evil under the Onimen Party's control. The battle between justice and evil begins now.