A satanic program is activated aboard a crowded commercial flight bound for Tokyo. The program releases a swarm of invisible demons, causing the aircraft to plunge into a fiery crash that kills everyone on board instantly, except Akito Kobayashi, the owner of the program and sworn ally of hell itself. Kojiro Soma, an old elementary‑school friend of Akito, is surprised to see him re‑enroll at school. Kojiro observes how the once‑lonely boy has transformed into a suave, arrogant teenager. Later, when Kojiro’s classmates are attacked and legendary demons begin to stalk the streets of Tokyo, Kojiro starts to understand the true nature of his former friend. Akito has plans for the human race, plans that revolve around…