From the introduction: In 199X, Kichijoji, Tokyo, a young man has a strange dream where he travels through an otherworldly realm to meet a crucified man, a man haunted by demons, and a woman who pledges to be with him eternally. After waking up, the youth discovers that a man calling himself Stephen has sent out a suspicious 'Demon Summoning Program' to any willing to use it, saying that humanity will need to use the power of demons in order to defend itself from them, as they have begun to rise from their ancient slumber. Curious, he downloads it onto his COMP before going out on an errand for his mother. Unfortunately, things aren't going well in Tokyo - the police are barricading many streets and people have started to go missing regularly.