Blood+: Souyoku no Battle Rondo is an action-adventure game for PlayStation 2 in which players control Saya Otonashi, a schoolgirl plagued by amnesia. After a Chiropteran attack reveals her unique abilities, Saya embarks on a quest alongside family and allies, including her chevalier Haji, to confront the Chiropterans and rediscover her lost identity.
Player assumes a role of Saya Otonashi — an ordinary schoolgirl, who suffers from amnesia. Upon being attacked by a Chiropteran she learns that she's the only one who can defeat them. She engages in a journey with her family, allies, and her chevalier Haji, to defeat he Chiropterans and recover her identity.