Three months have passed after the destruction of Red Shield HQ and Kai is now one of the most active members in Red Shield. He has been fighting chiropterans with enhanced arms and has become quite good at shooting. Lewis often accompanies him in the chiropteran hunts. After the HQ destruction, the number of chiropterans has rised notably. Now even civilian humans are aware of the presence of this monsters. Their numbers are highest in New York and that's why it has become the current base for Red Shield operatives.
Completing the usual hunt, Kai returns to the base. The next day, David and Julia expresses their doubts as to Saya's return since neither she nor Hagi has showed up yet. But Kai rages at them for thinking so. Since chiropterans are always after Saya and their population is the highest in New York, he still believes she is nearby. Just then Lewis comes with a bottle of calpis he has bought from the only importing store.
Kai recalls how much Saya used to love calpis and goes out under the pretense of taking a stroll. In his heart, he holds the firm believe in the reasoning that availability of calpis nearby, plenty of chiropterans' presence could only mean Saya is alive and she is nearby. Suddenly David calls him to warn him to relocate as quite a number of chiropterans are near him. Without arms, Kai climbs up to rooftop to evade chiropterans which indeed filled the place he was in minutes ago. He thinks they wouldn't notice him up there but another call gives him away. The chiropterans charge at him and just as one is about to strike Kai, he is startled to see it getting sliced from behind. As the body is slashed in halves, the gap reveals the face Kai has been long awaiting to see ~ Saya.
Saya is also astonished to see Kai there but their conversation is cut while another chiropteran jumps at them. Saya uses her blood to destroy it as well while Kai wonders at the power of her blood and realizes why she is called a 'weapon'. Suddenly Saya collapses and Hagi arrives just on time to grab her. Hagi ignores Kai's inquiry and does not even let him touch her. David shows up worried about Kai but finding Saya and Hagi, he tells them to come to the base to give her blood. Reluctant at first, Hagi agrees and brings Saya along.
Saya is given blood transfusion and put to rest while Julia takes David to discuss something in private. Kai remains outside Saya's room with Hagi and interrogates him why Hagi prevented him from getting near Saya. Hagi replies that it is what Saya has wished. For the past three months, Saya never wanted to look for Kai but only wished to annihilate chiropterans. Kai gets enraged at Hagi who shows him into Saya's room if he wanted to hear the same from Saya's own mouth. Kai accidentally wakes up a sleeping Saya and tries to get her back to rest but she gives him a cold look and tells him not to touch her. Kai, now totally shocked, asks if she was serious when she planned the double murder scheme with Diva three months ago and Saya confirms it. Kai gets furious and demands to know if she plans to murder Hagi and Riku as well since they're also chiropterans. Saya affirms that too as Hagi listens from outside. A flashback follows...
- After the shipwreck, countless unidentified bodies from the luxury liner were hauled off the Pacific coast. Massive outbreaks of humans turning into monsters started in Hanoi. Saya and Hagi having survived the wreck, sat on the coast. Saya recalled how Diva was never aware that she intended to kill her and all she wanted was to make a big family of chiropterans. But Saya couldn't let her turn the entire human population into chiropterans. So, she sacrificed her heart in order to fulfill her vow to rid the world of chiropterans.
Back at the present, Kai leaves Saya after hearing her cold words. Hagi enters the room to find Saya crying and embraces to comfort her.
Meanwhile, Julia shows David the analysis of Saya's recent and past medical reports. It all hints that Saya will soon reach her dormant period!
Suddenly some chiropterans break into the base as everyone hurries to face them. Saya fights despite her weakened state and one of them bites off her hand which regrows. However, more charge in before she could recover completely. To everyone's surprise, a guy enters and saves Saya from the chiropterans. He is followed by Riku and the clone Charles. Riku cuts off another chiropteran about to attack with his hand transformed to a blade. Riku explains that he asked the guy to teach him how to transform and introduces the guy as Solomon, Diva's chevalier. Everyone tends to get aggressive after the announced presence of Diva's chevalier but Solomon says he came to return Riku back to them unharmed. Riku affirms that he's a nice guy. Saya asks what he wants and Solomon kneels down and proposes her.
With the chiropterans annihilated, everyone gathers in the currently devastated living room with Saya and Solomon sitting at the center. Saya rules out Solomon's love at first sight theory which he tried to press on saying she looked beautiful while fighting in Vietnam. She tells him that he had the same look of curiosity as Amshel on mating of chiropterans. Solomon compliments her and asks how he might convince her that it is love at first sight. Saya agrees to believe Solomon only if he helps them kill Diva. Solomon admits that he wants to test the theory of chiropteran evolution but he also loves Saya and will prove that by helping them bring about the death of Diva.
A plan is formulated; Saya and her chevaliers, the Red Shield team, Charles' clone and Solomon position themselves where Diva is scheduled to perform. Solomon, Riku and Charles' clone engage Diva's bodyguards as Saya awaits to confront Diva.