S1, E1: A young woman called Yukimura Chizuru travels from Edo to the capital, Kyoto, in search of her missing father. Once there, she's nearly attacked by a monster who is thirsting for blood. The monster, a rasetsu, is slain by group of men feared as assassins, the top officers of the Shinsengumi—Hijikata Toshizou, Okita Souji, and Saitou Hajime. Chizuru stays with the Shinsengumi to search for her...