Watashi, Kyuuseishu Nanda. Maa, Ichinengo niwa Shideru ndakedo ne
私、救世主なんだ。まぁ、一年後には死んでるんだけどね
A girl named Kamishiro Fuuka is destined to die within a year, and she asks the narrator to be her boyfriend on their first meeting. As her partner, he accompanies her through various events listed in her "Savior Notebook" throughout the seasons. Despite her role as humanity's savior, she is revealed to be an ordinary girl. The narrator, who possesses the ability to use shadows and hunts evil, seeks a way to save her before her time runs out.