Female high school student Otonashi Saya (voiced by Kitamura Eri) has a happy family and a group of kind friends. Although she has lost all her memories from a year ago, this does not prevent her from enjoying the happy time in front of her. In this world, there are monsters called "winged hands". They have eternal life and feed on blood. Now, the existence of these monsters gradually threatens the safety of mankind. On the surface, Saya and these terrible monsters seem to have no intersection in their lives, but on this day in 2005, when the dark and ominous man appeared in front of Saya, everything changed. The man's name is Haji (voiced by Kosikshin). His arrival not only changed Saya's fate, but also evoked Saya's long-lost memories. In order to protect the world and the people she loves, Saya took up arms and began to fight with the winged hands with the help of Haji.