In the late Sengoku period, rival warlords tear Japan apart while hidden vampires quietly steer human power from behind retainers, monks, merchants, and survivors. Dayas becomes something outside their ancient order after eating a blood-red flower on an old battlefield. A newborn vampire with no maker, no rules, and unnatural strength, he threatens the secrecy that has protected the elders for generations. Near a burned village and a watched clan outpost, Dayas must learn what he is before hunger exposes the hidden world and brings the vampires down upon him.