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?!
Blue Elysium is a newly constructed, additional manmade isle off the Demon Sanctuary of Itogami Island: the latest, greatest resort, boasting pools, and an amusement park! Yaze schemes to invite Kojou and the others to the isle before its public opening, but somehow the "free" trip lands Kojou in a horrid part-time job. Meanwhile, Sayaka Kirasaka, Shamanic War Dancer of the Lion King Agency, visits Blue Elysium as well. Her mission: to rescue the mysterious girl Yume, held captive inside a research facility. But, an unknown Attack Mage appears before Sayaka, a "Priestess of the Six Blades" using the same techniques as Yukina!
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?
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!
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!
This is only the beginning... Chaos descends upon Itogami Island! Air and sea transportation have come to a grinding halt and key personnel from the Gigafloat Management Corporation are being assassinated one after another. The proud culprit behind this series of attacks is the self-proclaimed Demon Sanctuary destruction group, Tartarus Lapse. At the same time peculiar changes begin to occur within Nagisa as the soul of the Avrora bleeds into her consciousness. In her time of spiritual turmoil, a mysterious girl appears before her and introduces herself as "December." What Nagisa doesn't know is that this girl is the leader of Tartarus Lapse, and she has a special ability capable of overwhelming even the Fourth Primogenitor...!
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!
WHEN ALLIES BECOME ENEMIES, WHO CAN YOU TRUST? New Year's Day is right around the corner on Itogami Island, and everyone is getting ready to celebrate! ...Well, almost everyone. Nagisa, off on a trip to the mainland to visit her grandmother, hasn't been returning any calls or texts. Equally troubling is Yukina's sudden and complete loss of contact with the Lion King Agency. When Kojou and Yukina's frantic attempts to find answers reveal evidence of a magical incident, Kojou decides to risk everything and travel to the mainland to find Nagisa himself. But in hismost desperate hour, an unexpected adversary stands in his way...
He never asked for this power. Kojou Akatsuki used to be an ordinary high school boy--but that wasbefore he became the Fourth Primogenitor, the most powerful vampire of all time. Worse--he doesn't even remember how it happened. Middle schooler Yukina Himeragi, meanwhile, is the Attack Mage sent to observe him--and to stop him if he gets out of control. But was it really a good idea to send a cute girl to observe a massively powerful vampire boy whose abilities activate whenever he gets aroused? And on an artificial island populated with all manner of demonic individuals, each with their own designs on the Fourth Primogenitor--?!