In an alternate Meiji Era, Sakamoto Ryunosuke returns to Kyoto from Shanghai accompanied by his youkai, Nekomaru. The law requires that a youkai obtain a license to coexist freely with humans. The Kidou Shinsengumi Co. Ltd. is tasked with apprehending unlicensed youkai, but it must confront the Tsubamegumi, a faction that resents the new law. Ryunosuke learns that he is the son of the company’s owner.