What should have been a simple day out with friends turns into a mysterious disaster when powerful demonic beasts appear. Kazuya and Atsuro were supposed to meet Naoya, their enigmatic friend, but he doesn't show up and instead sends another friend, Yuzu, to meet them and give them specially modded gaming devices. It becomes apparent that Naoya has given them much more than they bargained for when demons spawn from these devices!
The situation for those trapped within the Tokyo Lockdown grow more and more dire. Already on day three, Kazuya and his friends must adapt quickly–together and on their own–before time runs out. When the battle against Beldr finally seems to be over, the King of the Undead rises once more for a grisly rematch. But behind all the fighting lies a terrible secret that finally comes to light…