After the battles of Kyoto and Nerima, the students of Rasetsu Academy have grown stronger. But Yaoroshi leaves the academy to join the Oni Brigade and complete his mission to completely exterminate the Momotaro. When Shiki discovers they are also attacking civilians, he sets out to find Yaoroshi and bring him back. Meanwhile, in Nikko, a research facility where horrific experiments are being conducted arises above the ancient Kegon Falls...