A young woman walks into a tunnel alone at night. Suddenly strange trenchcoat-wearing figures melt out of the walls, surrounding her and chanting, ""Come to our world!"" Ayane Isuzu, a high school girl, emerges from the darkness and single-handedly defeats the creatures, saving the woman. Nearby, Miyu Manadzuru, another high schooler, avoids a pushy companion by ducking into an alley and flying into the sky. Ayane spots the flying girl in the night sky. At school the next day, Ayane is revealed to be a cynical loner, known as being into technology and labeled a weirdo. Meanwhile, an inspector looking into a car accident finds one of the trenchcoat-wearing figures in a wrecked man. The figure disappears, leaving a small crystal behind. Ayane meets with Nazo, a mysterious older man who tells her to seek out Miyu since Miyu's a Gate Keeper. Ayane also gives him a bag of crystals (what's left of the Invaders she fought) in exchange for money. That night, Ayane invites Miyu to join her so Miy

Satoka meets a new student in class. Outside, Ayane wistfully watches some birds. Later, outside the school, Miu asks Ayane about Satoka and Satoka's powers. Suddenly, Satoka appears and reveals that Ayane is the only daughter of legendary Invader-hunter Shun Ukiya. Satoka asks why Ayane took her mother's maiden name, given her dad's achievements. Ayane slips away without answering, angering Satoka. Count Akuma Hakushaku, an Invader, tells the blonde ghost girl his strategy of luring victims with the smell of honey and then poisoning them. Satoka fruitlessly tries to find out about Ayane from Miu. After Satoka leaves, Yukino appears to Miu and quotes more cryptic poetry. Ayane visits Miu at her place of work and criticizes her for putting up a false, friendly front when she's actually being selfish. Reiji picks up Invader activity, and Satoka races to its location. Satoka slaughters the Invaders using her Gate of Blades. It looks like she's all done by the time Ayane arrives. Excited b

As school lets out, Miu's friends invite her out, but she leaves them and visits Reiji and Ayane at Headquarters. Reiji has been taking care of Ayane, who's been in a coma for four weeks. Reiji talks about how Ayane hated the city, and how the city's corruption breeds Invaders. He shows Miu the storeroom of crystals from vanquished Invaders. He says that one day he hopes to be able to turn these crystals back into humans, even though the chances are slim. He also wonders why, despite her hate, Ayane continued to bring the crystals back to him instead of destroying them. The blonde-haired Ghost Girl enters Headquarters and hovers over Ayane. She says Ayane is just like her. Reiji opens his Black Gate on her, but she isn't absorbed. He realizes she isn't an original Invader, but a human. Using her own Gate powers, the Ghost Girl blasts Headquarters apart, takes back all the collected crystals, and disappears. Reiji reveals that he's partly prosthetic because his use of Gate Powers consum

Reiji, Yukino, and Satoka gaze, from a safe distance, at the mammoth Invader machine growing larger by the minute. Reiji says it's hopeless, but they must fight anyway. Miu visits Ayane, who's still in a coma. Miu confesses to the silent Ayane her weakness and her dream of flight. Reiji harms himself fighting the winged Invaders. Satoka raises a huge blade from her Gate and foolishly plunges into the attackers. Yukino teleports to the top of the Invader machine, right next to Ghost Girl. Ghost Girl reveals that her Gate of Disappearance made her what she is. The two face off. Yukino's ice pierces Ghost Girl but doesn't harm her. However, Ghost Girl's blast knocks Yukino off the Invader construct. Miu flies up and catches Yukino, but Yukino's deeply wounded. Yukino disappears in Miu's arms, leaving behind only the uniform Miu gave her. Miu flies up to fight the Invaders, but her power leaves her half way up and she plummets to the ground. She lies surrounded by winged Invaders. Meanwhil