Hakuoki is a Japanese manga and anime. In the story, the main character is a girl named Chizuru Yukimura. She is a member of a family of Rangaku scholars. Her father is a well-known Rangaku scholar named Chizuru Hirata.

When Chizuru was young, she lost contact with her father. She decided to go to Kyoto to find out what happened to him. She was told that he was killed by a monster. When she reached Kyoto, she witnessed the killing of a monster by a Shinsengumi soldier.

She was given an invitation to a tea party on the behalf of her father. She accepted the invitation and went with the Shinsengumi warriors.