As fate would have it, Yumiko Shirasagi finds herself in the same class as Akemi Nakajima, a high school student with unparalleled computer programming skills. Although they have never met before, Shirasagi feels an inexplicable bond with Nakajima. After school one day, Nakajima and a few of his classmates perform a summoning ritual to conjure the devil, using his technological savvy to call upon Loki and offering up a female sacrifice. What will become of Shirasagi's future after witnessing this harrowing event?