While Hatsume, who manages to remove Moryo's drug from Therisia's body, stays behind with Mei, Momo, Yuki, Fu, and Goe go to Okinawa, where they come across a mysterious helmetted girl. As the girls look into an organisation known as Nirai Kanai, they learn that the girl from before, Ouka Miyaume, is being forced to work for them after her grandfather was taken hostage. While the others head to Nirai Kanai's base to obtain their data and rescue the hostage, Goe faces off against Ouka and convinces her to join their side...