Saya and the others follow a container cargo carrying Diva who was transported out of the lycee. The operational unit of the Red Shield, Clara, Spencer, Rogers and McCoy, joins the pursuit. They go upstream on the Mekong River and head toward the experiment farm of Les Cinq Fleches Pharmaceutical. The farm had collected children from all over Vietnam. Mui, Riku and Kai were among them. But Saya and her friends are not aware of this fact as they get ready for the showdown...

At the experiment farm of Les Cinq Fleches Pharmaceutical, Saya is surrounded by child Chiroptera. But confronted with a mysterious humming coming from nowhere, the howling of the Chiroptera and a choking smell of blood, the girl goes berserk, and swings the sword at anything that comes into her view without even distinguishing between friend and enemy...