School. Biology Room. Night. Kai, who has come to pick up Saya, witnesses an incredible scene: her sister covered with blood is fighting with a sword against a creature beyond any description. Then Saya faints on the spot... The next day, the incident is treated as a murder committed by a drug addicted American soldier, and there seems to be no trace of the creature. Taken to the hospital from school, Saya accidentally hears the conversation between George and David, a mysterious man who watches over Saya. And what she hears makes her run away terrified...

Saya and friends return to Okinawa for a brief time. They decide to do whatever they wish on this one-day break. Saya, Kai and Riku bury George's memento in his grave. And Saya meets her best friend Kaori at the Yaejima Park.

Kai at last is reunited with Saya, but the girl faints from exhaustion. Kai brings Saya to Glay's home to take care of her, but the enemy is again lurking in the darkness ready to attack...

Solomon, accompanied by Nathan, shows up before Diva. He transforms his right hand into blade and charges to slash her. Meanwhile, Julia continues her study on D-base in Diva's blood, and realizes that the effect of synchronicity caused by Diva's singing could infest the entire world with chiroptera...