Akai Ren, a young High School drop-out, was on the verge of losing his life when he was found by a mysterious lady with a revolver tattoo. His almost die experience changed his life forever, leading him to a world he’d never known ever existed. For centuries, a secret organization known as Soshiki has operated in the shadows, dedicated to protecting humanity from ancient evils and monstrous threats that lurk just beyond the edges of reality. Founded during the height of Jōmon Period, the Soshiki emerged in response to the rise of dark forces called the Spectres—demons, supernatural entities, and powerful sorcerers that threatened to plunge the world into chaos. Composed of skilled warriors, Soshiki has passed down its knowledge and practices through generations, evolving with the times while remaining hidden from the eyes of the ordinary world. Will the ordinary Akai Ren be accepted into the organization? Will he fit in? Why did he get invited to join by the mysterious lady in the first place?