This is a game developed by Grasshopper Manufacture set after episode 7 of the Blood+ anime. Players alternate between sequences starring anime protagonist Saya Otonashi and original character Kou Aoyama. Gameplay consists of exploring the town where the game is set, talking to NPCs and eventually engaging in battle with Chiropterans or a boss.
Despite being based on an anime, the vast majority of characters and scenarios in this game are original creations by Suda. The game is considered non-canon.