Jinrou Shitsuji no Bussou na Nikka

For centuries, werewolves have lived in subservience to vampires, acting as loyal servants and wagging their tails at the command of their blood-drinking overlords. However, a young werewolf named Phil is determined to break this long-standing cycle. Driven by the mysterious disappearance of his father, he vows to exact a calculated revenge against the vampire race. To achieve his goal, Phil goes undercover and secures a position as a butler in the household of Eric Beaufort, the most renowned and dangerous vampire in existence. Yet, carrying out his vengeful plan proves far more complicated than Phil ever anticipated. Despite his fearsome reputation, Eric turns out to be unexpectedly warm, friendly, and genuinely kindhearted, completely contradicting everything Phil believed about his kind. Furthermore, every traditional anti-vampire weapon and tactic Phil attempts to use against his new master fails entirely. Caught between his burning desire for retribution and the disarming nature of the man he serves, Phil finds himself trapped in a perilous yet comical dilemma, struggling to figure out how he can possibly eliminate a master who refuses to act like a monster.