In Edo during the Tenpo 14 era, Yoi beings from a different dimension invade, prompting the Bansha Aratemesho to defend against them. Although they are recognized for their research on foreign literature, this group is devoted to eliminating the Yoi. Dubbed as Ayakashi, the members detect unusual occurrences nationwide before battling the invaders. Their distinct traits include a man with memory loss and a female who disguises herself as male, all of whom possess superior skills to conquer the Yoi.