When the world is under attack by a monstrous and unstoppable enemy, the only way to fight back is with warriors who have already died! Sidestepping a gruesome fate in a subway crash, Hibiki, Daichi, and Io find themselves recruited into the ranks of the Devil Summoners! When each clash comes with a clock counting down to Armageddon, it’s the ultimate conflict between good and evil, as the living, the dead and the demonic combine forces to send the invaders straight back to Hell.
Nicaea, a "dead face delivery site" is rumored to send photos of people at the time of their death. When Daichi and Hibiki, two friends about to graduate, are suddenly killed, they are revived by Nicaea and sent into a battle between humans and demons.
Three friends are thrust into a war they never asked to be a part of, wielding demons that they summon through their cell phones to battle the invading Septentrione, with the entire world at stake.
Daichi and his friends are transferred to Osaka, where they meet two new Summoners. Actually getting to know them will have to wait, as their new city finds itself under attack by an old foe.
Hibiki struggles with his failures while Osaka's defenses come up short. Meanwhile, a new enemy has made itself known and is intent on destroying all who oppose it.
Professor Kanno fervently works to restore they Terminal tech from scratch as the Septentione ready themselves for a new assault. Io and Daichi search for Hibiki in Nagoya, but instead discover a band of insurgents opposing JP's.
The three friends are reunited just as a new Septentrione attack is under way. Two former JP's members join the fray to help battle the new threat.
Ronaldo and Yamato reach an uneasy truce and decide to work together. With an imminent attack looming in the distance, they decide to split protection of three cities between them.
The three entities of the Septentrione have finally manifested and are heading straight for Tokyo, Osaka and Nagoya. Hibiki, armed with secret knowledge must find a way to stop the enemy advance.
Hibiki, dazed but in good shape, awakens on Thursday to find a guest in his quarters: Alcor. Is he still a threat, or has he changed his ways?
To defeat Mizar, JP's will summon a powerful demon; unfortunately, controlling it will mean trapping it in a human vessel that is bound to be destroyed.
The seventh Day of Judgment has arrived, leaving a path of destruction in its wake. With Hibiki still in a coma following the previous day's encounter, Daichi and the others will band together in an effort to stop it.
The battle against the Septentriones is complete, and the final battle line has been drawn. The Void continues to expand, devouring all of existence, and Alcor and Yamato finally resolve their long-brewing conflict.
No longer afraid to fight, Hibiki remembers his promise of having an audience with Polaris. Driven by anger, he ventures forth for answers.