Long ago, a Shinso ("First Ancestor" in English manga) named Alucard tried to wipe out the human world by absorbing countless other monsters to gain the power necessary. Another Shinso and her two comrades fought and defeated Alucard, using her power to seal him away in eternal slumber (which was a grave miscalculation). Because of their exploits, these three later became known as Three Dark Lords. In the present, Akasha is within Alucard, while Mikogami and Touhou are locked in combat with the monstrosity, aided by the Siren, San Otonashi and new Shinso, Moka Akashiya and Tsukune Aono.