Japan, Okinawa Prefecture, Okinawa City, Koza District. Saya is a senior high school student, and with her best friend and classmate, Kaori Kinjo, she is a member of the track and field team at school. She lost her memories of her life beyond that of the past year, but she is living peacefully with her family. His father, George Miyagusuku, runs a pub called "Omoro." She also has two brothers, Kai, hot tempered but actually kind and committed to his family, and Riku, who is good natured and loves to read. But Saya's unruffled life is about to change: when she accidentally meets a handsome cellist, Hagi, it is a sign that the wheel of fate has begun to turn...

The memory of that terrible night is fading away: not a trace is left, and a brand new desk is placed in the biology room, as if nothing had happened. On her way home from school, George takes Saya to the grave of the Miyagusuku family, on a hill overlooking the sea colored by the sunset. George talks about his past and his meeting with Saya. Back at Omoro, David reveals to Saya that she is the only living being who can defeat the chiropterans, as the creatures like the one that attacked her at school are called. Saya is shocked, but a new menace is just approaching, its eyes shining red...

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.

Mao gets frustrated for not being able to see Kai and she feels left out. Okamura, the Ryukyu Daily reporter, cannot forget about the sight he witnessed in the wine barrel storage at the lycee in Vietnam.

Mao wants to pursue Kai.

Okamura wants to find Saya to solve the mystery of what he saw. Then, two people with the same goal and different motives meet...

James comes to see Solomon who was gravely injured by Diva and is confined. James, intending to bring despair to all of mankind, declares to Solomon that he would eliminate Saya. Meanwhile, David with Kai and others start an operation to stop the live broadcast of Diva's opera performance around the world. As Saya remains sleeping in her NY apartment with Hagi and Lulu, James approaches with a deadly blade...

With much anticipation around the world, global live satellite broadcast of Diva's concert in New York begins. To stop Amshel's plan to fill the world with chiroptera using the Synchronicity effect of Diva's singing, Saya and Hagi sneak into the backstage and get ready for the final battle. Meanwhile, Nathan talks to Amshel and reveals his astonishing identity!!

As Saya sees Diva's babies, she hopes no one will be hurt. She takes her sword and brings the point up slowly. At that time, the US army was about to carry out a plan to erase all evidence of the Chiroptera...