Airi and Jungo sneak into the JP's Nagoya Branch through the air ducts, while elsewhere, Daichi and Io rush to Hibiki's location in order to prevent his death. As Ronado, Hibiki, Joe and Otome scout the Nagoya TV Tower in anticipation of the third Septentrione, Otome is hesitant to fight, especially when the JP's members such as herself have been told little to nothing about the Septentriones, although Ronaldo states that they should have no problem since their demons are much stronger than those used by JP's summoners. At the same time, as Hibiki ponders on Nicaea's origin and his power. Later, back at the Nagoya Branch, Otome and Hibiki have a brief discussion comparing Yamato's methods versus Ronaldo's methods. At this time, Daichi and Io arrive and tell Hibiki about his death clip while Makoto covers for them at the JP's Headquarters. Daichi and Io try to get Hibiki to return with them but he states that he can't because of the imminent Septentrione attack.
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.
