Katsugeki Touken Ranbu takes place in 1863, during the Bakumatsu period in Edo, where Izuminokami Kanesada and Horikawa Kunihiro, humanoid manifestations of Toshizou Hijikata's swords, arrive from the future. They have been sent to investigate reports of an impending enemy invasion and protect history from the Retrograde Army, which seeks to alter the course of events. This army is comprised of other sword warriors, who have also been pulled from different eras, making the duo's battles a complex and challenging endeavor.