The chaos of the Sports Festival becomes the perfect stage for death. Seeking to protect Aoi, Yodaka passes his duties to Umineko, but this retreat triggers a catastrophe. A deadly assassin, Mukuro, infiltrates the school, targeting the forbidden seal hidden on Aoi’s chest. As the field descends into carnage, the mask of their ordinary life shatters. With forbidden arts unleashed and the school turned into a battlefield, Yodaka is forced to confront a terrifying evolution in Aoi that threatens to consume them both. The secret of the seal is finally crumbling.