The terrorists launch an attack upon the warehouse district. Afterward, Kojo and Himeragi meet the terrorist leader, Senga Takehito, who tries to recruit them. He reveals his beliefs about the true nature of the island, its purpose of reviving Cain, and his plans to oppose this.

After the terrorist incident on Itogami Island, Kojo and the others are helping with the Island's recovery. On the other hand, Asagi, who gained popularity with the public for preventing hacking in the past incident, works as an ambassador for revival activities for the Island Management Corporation. However, Kojo feels like something is off when he sees Asagi on the big screen.

Kojo and the others go to rescue Asagi, who was imprisoned on the 0th floor of the Keystone Gate. Kojo is worried about Himeragi's poor condition, but Himeragi goes with Kojo nonetheless. What was waiting for Kojo and Himeragi on the 0th floor?

Itogami Island had returned to a peaceful state and Kojo's party was getting excited about the upcoming Valentine's Day. Meanwhile, Kojo sees Asagi getting into a car with one of Vatler's subordinates, and starts to get suspicious. Grenda, who was with Shio and Yuiri, is attacked by Veres Aladar, the Imperial Council Chairman of the Warlord's Empire. Grenda flees to Itogami Island, where Kojo is located.

Kojo wakes up at Natsuki Minamiya's house. On TV, Asagi and Vatler appear to be working together and declares war against the Holy Ground Treaty Organization. In addition, Asagi says that Grenda will use Cain's legacy that she has protected as her power, to help save Itogami Island. Meanwhile, to save Nagisa, whose life is in danger, Hektos tells Kojo and the others that she will need to hold a ceremony.