Hibiki is put into intensive care at the JP's' Tokyo Branch. As the demon summoners look on, Io can't help but feel responsible for his current condition, although she is comforted by Jungo and Airi. Meanwhile, Alcor is visited by Botis and Bilfrons, the former of whom tries to attack him because of his supportive stance on the humans. Fumi updates the JP's phones with software capable of summoning stronger demons. The next day, Io, Daichi, Airi, Jungo and Hinako have breakfast together in a single moment of peace and officially introduce themselves to each other. As they go to exchange emails, they all simultaneously receive each other's death clips. Suddenly the last Septentrione: Benetnasch appears and destroys the Sapporo barrier with a single attack allowing the Void to consume the region. As Fumi outlines that it possesses the abilities of its predecessors, the Osaka and Nagoya regions are wiped out each with a single blast. Yamato then orders everyone to begin the operation.
The countdown to extinction begins on Sunday with the arrival of the Septentriones, otherworldly invaders set on the eradication of mankind. Caught in the crossfire, Hibiki Kuze and his friends join in the war for humanity's survival by signing contracts with demons to become "Devil Summoners." Soon, their abilities attract the attention of JP's, an underground agency led by Yamato Houtsuin. Once recruited into JP's, Hibiki and his friends fight and bond alongside other ordinary citizens who are Devil Summoners.
However, with each new day, another Septentrione appears to wreak havoc upon Japan. Even if many lives are lost in the process, before that night ends, the young summoners must defeat the invaders at all costs.
