Mikumo, Gakuto

Nagisa is away on a trip to the mainland, visiting her grandma, and has not been returning her friends' calls or texts. Yukina, then, more worrisomely, loses all contact with the Lion King Agency, and when she and Kojou attempt to find answers they discover evidence of a magical incident, prompting Kojou to risk all and go to the mainland to find Nagisa.

Chaos erupts on Itogami Island as key personnel from the Gigafloat Management Corporation wind up assassinated, one after another. The culprit is the self-proclaimed Demon Sanctuary destruction group called Taartarus Lapse. Meanwhile, the soul of Avrora has been bleeding into Nagisa's consciousness, even as the mysterious girl "December" appears, who is the secret leader of Tartarus Lapse.

At the sealing ceremony for the relic of The Cleansing, the former Fourth Primogenitor who was sealed within Nagisa awakens, surging with magical energy and causing the calamitous being at the bottom of Lake Kannawa to wake up and threaten the world.

Kojou and Yukina join forces with Natsuki Minamiya to protect Itogami City, but when Kanon Kanase disappears, Kojou and Yukina may find that there are some problems not even the world's mightiest vampire can solve.

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?.

When all the students depart for a school field trip to the mainland, Kojou is delighted to hear that he'll finally get a chance to be free of observation for at least a little while, whereas Yukina has mixed feelings about the whole situation. But events move quickly when an alchemist by the name of Kou Amatsuka appears, with the goal of reviving the holy grail of alchemy--a liquid-metal life-form known as "Wiseman's Blood." As the crisis deepens, even Asagi becomes involved when this alchemist's relic grows more and more uncontrollable. What can the world's strongest vampire do?!.

Itogami Island is abuzz with preparations for the Halloween festival, and who should be visiting for the occasion but Kojou Akatsuki's friend from elementary school, a girl named Yuuma Tokoyogi. But as Kojou reunites with his friend, his homeroom teacher, Natsuki Minamiya, goes missing! Meanwhile, a strange space-time distortion is turning the sanctuary of Itogami Island into a labyrinth from which escape is impossible. And what's behind the physical changes that come over Kojou whenever he has physical contact with Yuuma? The long-awaited fourth volume of the light novel series is here!.

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!.

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!.

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!.