In a world where vampires closely resemble humans genetically, distinguishing them is no easy task. However, the key difference lies in their uncontrollable urge upon seeing human blood. When vampire Shouta Akimura becomes smitten with ordinary girl Tsukasa Taira, he struggles to contain his bloodlust, resorting to preying on others to protect her. Walking a dangerous line, Shouta risks succumbing to his primal instincts at any moment. To shield Tsukasa from harm, vampire detective Yuuki Anzai intervenes, rescuing her from becoming Shouta's prey. As Anzai escorts Tsukasa to safety, she becomes captivated by this vampire savior. Their unlikely bond leads them down a treacherous path entwined with a dark web of conspiracy, murder, and suspense.