Strike the Blood Light Novel Series by Gakuto Mikumo, Manyako

Kojo Akatsuki used to be an ordinary high school boy--but that was before he became the Fourth Progenitor, 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... moreKojo Akatsuki used to be an ordinary high school boy--but that was before he became the Fourth Progenitor, 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--! less

The friend of my friend is my enemy?!Akatsuki (an ordinary high school boy and incidentally the world's mightiest vampire) is finally getting used to daily life with Yukina Himeragi, the attack mage whose job it is to observe him. But his peaceful life is interrupted by the appearance of Dimitrie Vattler, an envoy from the European primogenitor known as the "Lost Warlord... moreThe friend of my friend is my enemy?!Akatsuki (an ordinary high school boy and incidentally the world's mightiest vampire) is finally getting used to daily life with Yukina Himeragi, the attack mage whose job it is to observe him. But his peaceful life is interrupted by the appearance of Dimitrie Vattler, an envoy from the European primogenitor known as the "Lost Warlord." Vattler's enough of a problem, but it turns out he's got his own watcher, who's friends with Yukina--and who wants Kojou dead. Worse, their arrival is only the prelude to the emergence of a dark conspiracy that threatens the entirety of Itogami Island! less

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!

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... moreItogami 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! less

Aya Tokoyogi and six other hardened magical criminals have broken out from imprisonment. Their goal--to completely erase the 'Witch of the Void,' Netsuke Minamaya, from existence. How these events will unfold in the Demon District will depend on the actions of the strongest vampire to ever exist, Kojou Akatsuki.

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

When Kojou Akatsuki went to visit his sister in the hospital in middle school, he met a vampire named Avrora. Once he learned she was the key to saving Nagisa's life, he helped Avrora escape. Now, the weapons dealer Zacharias is telling him to hand over Avrora in order to rouse the fourth primogenitor! As Zacharias's plans plunge Itogami Island into peril, the fourth primogenitor finally awakens...

A New Year on Itogami Island is right around the corner, and for Kojou and Yukina, that means cutting off their contacts and returning to the mainland for a top-secret rescue mission. Coincidentally, this also means zero contact between Yukina and the Lion King organization. Can the fearful duo see their mission through to the end, or will they be overwhelmed by an unexpected enemy?