Shizuma Origasa, a former Aizu Domain samurai, fought on the losing side of the 1868 Boshin War. Witnessing his comrade Gen'nosuke's death, he swore to protect Gen'nosuke's sister Sumie Kanomata. This oath drives Shizuma's relentless search for Sumie after she vanishes in the war's chaos. By 1874, Shizuma works as a rickshaw puller in Tokyo. His life unravels when a passenger, assassin Takechi, implicates him in an attempt on Minister Iwakura Tomomi's life. While clearing his name, Shizuma confronts Takechi, showcasing combat skills that impress Imperial police Chief Superintendent Toshiyoshi Kawaji. Kawaji recruits him into the new police force. The position grants Shizuma legal access to government resources for his search, yet he clashes with the force's rigid discipline. An altercation with bullying Chindai soldiers earns him menial tasks like collecting stray dogs. His samurai-honed swordsmanship surfaces during the Gekkenkai fencing tournament, where he competes undercover to investigate swordsman Tachibana Youjirou's murder. The tournament escalates when finals shift from wooden swords to live steel. Stoic and honor-bound, Shizuma displays fierce loyalty, particularly toward his partner Hidenobu Osanai. Investigating the "hunting club"—a group abducting people for sport—he acts without authorization to rescue victims like Koume, highlighting his proactive instincts. His journey entangles him in Meiji-era conspiracies, including Buhei Hiramatsu's plot to overthrow the government and assassination attempts on figures like Minister Ōkubo Toshimichi. He repeatedly crosses paths with Kyōshirō Shuragami, a formidable swordsman within the Moriya yakuza clan. Through Tokyo's turbulent underworld and political strife, Shizuma's quest to find Sumie Kanomata remains his unwavering compass.