After partnering with Natsuki Minamiya to capture the Masked and end the destruction in the sky, Kojou and Yukina are shocked to discover one of the winged girls is none other than Yukina's classmate Kanon Kanase! When Kanon disappears, Kojou and Yukina seek out her adoptive father, a researcher at megacorp Magus Craft, Inc. Far from the professional meeting they expected, the two find themselves abandoned on a deserted island! It is deserted...isn't it?!

Nagisa has collapsed! Kojou rushes to the hospital, but suddenly a mysterious girl appears, and she looks just like Avrora, the former Fourth Primogenitor. She backs Kojou into a corner--but is she the real Avrora? Through this encounter, Kojou regains his lost memories, what will he remember? Finally, Kojou's past and the secrets of the Fourth Primogenitor are revealed!

Kojou Akatsuki lives on the artificial island of Itogami, and he has a secret: He's the "Fourth Primogenitor," the most powerful vampire in the world. He's carefully kept this dark knowledge from his family and friends, but one day, a beautiful girl named Yukina Himeragi appears before him and tells him that she knows who he really is--and that she's been sent to...kill him?!

NO REST FOR A PRIMOGENITOR… It’s a new term at Saikai Academy, and fortunately for Kojou, hehasn’t been held back a year! Freed from his constant work defending Itogami Island, he is ready for some peace. However, an entirelynew demon beast appears, and when Rui and Yuno are dispatched to deal with it, they are gravely wounded. Kiriha forms an unlikelyalliance with Shizuri, who is dead set on avenging her friends. Meanwhile, the Japanese government has concerns about Yukina’s ability to continue observing the Fourth Primogenitor, so the Lion King Agency readies a replacement. As Yukina frets over this threat to her position, her stress only grows with the arrival of a mysterious girl who looks exactly like her!

Yukina is trapped in a pitched battle against Astarte the homunculus, and she's losing--when who should come to her rescue but the very boy she's been assigned to observe, Kojo Akatsuki! Akatsuki tries to end the clash, but Astarte's familiar, the fearsome Rhododactylos, isn't going to let that happen. Is this a fight that only an awakened Fourth Primogenitor can finish?

THE REVIVAL OF THE TRUE FOURTH PRIMOGENITOR IS NIGH! When Kojou Akatsuki was a junior high school student, he met a vampire named Avrora...and then he saw her again when travelling to the hospital to visit his sister. When Kojou learns this mysterious, quiet girl could be the key to saving Nagisa's life, he helps her escape the Magna Atraxia Research lab. With the arms dealer Zaharias planning to use Avrora in his Blazing Banquet, can Kojou stop the revival of the true Fourth Primogenitor and save Itogami Island?

Time is running out for Kanon Kanase. If they can't stop the faux-angel ritual in time, she'll ascend from realm of mankind and become something truly inhuman. Will the Fourth Primogenitor be strong enough to stop this madness before it's too late? The Amphisbaena arc reaches its heart-pounding conclusion!

A civil war suddenly erupts in the Chaos Zone, the Central American empire ruled by the Third Primogenitor. Kojou & Co. sense that someone is backing anti-government forces from the shadows. Suddenly, a mysterious suitcase arrives at Kojou's apartment from the Chaos Zone - and the sender is Dimitrie Vatler. Inside the suitcase sleeps a mysterious foreign girl named Celesta. Kojou and Yukina look after Celesta while she, regarding Vatler as her savior, disparages the two of them with a poisoned tongue. However, Celesta, the "Bride" of Zazalamagiu, harbors a frightening secret unknown even to her-!The long-awaited tenth volume of the school action fantasy series about the World's Mightiest Vampire and the man-made island of never-ending summer!

Kojou and Yukina join forces with Natsuki Minamiya to protect Itogami City from a new threat from the skies--but even Kojou's Beast Vassal can't take this new foe on, and who should rescue them from their predicament but Kojou's sister's friend, a silver-haired girl named Kanon Kanase! But when Kanon disappears, Kojou and Yukina may find that there are some problems not even the world's mightiest vampire can solve!

FOREVER…IF POSSIBLE ​ The Merciless Queen, a high-ranking commander unit for the Legion, has finally been taken into custody. Now the Federacy, the United Kingdom, and the Alliance of Wald can conduct a thorough analysis of this special Ameise, which houses the consciousness of Legion developer Zelene Birkenbaum. If their efforts bear fruit, they may learn the secret to stopping the Legion once and for all! In the meantime, the Federacy has decided to rest its battle-worn blades. The Eighty-Sixth Strike Package has been allowed leave for the first time in ages. As they arrive in the Alliance of Wald’s territory, they are able to step away from the iron and blood and enjoy a rare vacation! And it seems that two members of the Strike Package are getting a bit cozier than the rest…