The royal heir Chloe, who was brutally assassinated by her cousin, accidentally stumbles into the ancient vampire Arthur's lair. The two unintentionally form a blood pact that binds them together, kicking off a chemistry of mutual use. To use the vampire's powers to get revenge and humiliate the villains, the bright young princess transforms into a little maid, enduring everything; to get the heroine’s blood plasma to restore his memories, the stoic vampire is forced to become her personal bodyguard, always on call. What started as mutual exploitation unexpectedly turns into genuine feelings, and when the real danger arrives, they realize their love for each other transcends a thousand years.
