Strange occurrences at sea result in Itogami Island becoming isolated. Nagisa continues to suffer effects from her previous exertions. A terrorist group known as Tartarus Lapse begins operations on the island.

At Mogwai’s urging and with Motoki’s assistance, Asagi makes her way to the Keystone Gate in order to end the hacking attack upon the island’s network. Meanwhile, Kojo and Himeragi battle ineffectively against the demons unleashed by the terrorists.

Kojo and the others are helpless by the power of Meiga Itogami's Cleansing ability. Kojo wonders what the hell this Cleansing ability is. At that time, the truth about the Cleansing is passed on to Kojo. Will Kojo be able to protect Himeragi and Itogami Island from Meigawa Itogami?!