Throughout the passage of time and the shifts in backgrounds, a particular war continues to leave its mark on history, extending its influence into the modern world. There are two major groups involved in the ensuring war. The first group consists of monsters known as Chiropterans who can change their appearances into that of human beings. They are actually immortals who feed on the blood of the living. The second group is an organisation known as the "Red Shield", formed to track down these monsters and exterminate them. Otonashi Saya is a high-school girl who lives a peaceful life with her family. The only problem is, she has no recollections of her life beyond that of the past year. However, her happy life will be destroyed by an event that will lead her to her destined fate.

Picture	Name	Description
	Saya Otonashi	High school senior Saya Otonashi doesn’t remember anything that happened before one year ago. Despite the lack of memory, she lives a happy life with her adoptive family--that is, until a blood-sucking vampire called a “chiropteran” attacks her and her brother. The attack triggers the unraveling of her past, and Saya soon discovers that she is the only one who can defeat the chiropterans. With the help of her family, friends and her faithful servant, Hagi, Saya starts to revisit her past life and accepts her role battling the vampires that have plagued Japan for centuries.
	Argeno	Agreno is a Frenchman in Japan trying to track down two Chiropterans, which he calls mice. He has an unusual affectation for hard candy.
	Chiroptera	Chiropterans are human-like monsters who emerge with strong bat-like characteristics and the need to drain the blood of humans.
	David	David is a member of Red Shield, an organization formed to track down and destroy Chiroptera.
	Haji	A handsome cellist with some alarming Chiropteran features, Haji presents Saya with the special sword she uses to kill Chiropterans. He is somehow tied to her forgotten past.
	Riku	Saya's younger adopted brother. He's a smart and obedient boy with a fondness for cooking.
	Kai	Saya's older adopted brother is one of the most popular students at school, a former baseball star. He is very protective of both his siblings.