Blood and fangs

Humanity shares its world with two powerful groups, vampire hunters, who summon silver weapons and wield special abilities to protect the innocent, and vampires, bloodthirsty creatures with superhuman senses, rapid regeneration, and unique powers, weakened only by silver, garlic, holy water, or stakes. Sunlight holds no fear for them, but centuries of hunting have driven them almost to extinction. Most are common or noble vampires, purebloods, ancient, nearly unkillable beings, are thought to be gone forever.
Two organizations stand at the center of this world, the Port Mafia, made up entirely of elite hunters, and the Armed Detective Agency, a mix of ordinary humans and a handful of hunters. Chuuya Nakahara, a feared Mafia executive and one of the strongest hunters alive, has just learned his former partner Dazai Osamu is now working for the enemy.
What almost no one knows, least of all Dazai's new colleagues, is the truth: Dazai is a pureblood vampire, the very kind the world believes vanished long ago.
Years ago, the Mafia struck a deal to keep him hidden, as long as he never harmed their leaders. Dazai is unlike any other vampire: he can go a whole week without blood, yet he is helplessly, hopelessly addicted to only one thing, Chuuya's blood. Now Chuuya is determined to bring Dazai back, unaware of how deeply their tangled past, and Dazai's deadly secret, could unravel everything.