Luna, a rabbit clan herb gatherer, healed the mute vampire prince Kaian with her bright chatter in childhood and gave him a moonstone rabbit carving as a token to meet again. Eighteen years later, Kaian rules the vampire realm, yet Luna’s stepsister Vivian steals her identity. The real Luna enters the royal court under the alias Lily, drawing near Kaian with her skills as an apothecary and translator. Through suspicion and schemes, they finally recognize each other. Vivian’s lies collapse when her fake pregnancy plot and poisoning of the vampire queen are exposed. The false queen gets her due punishment. Kaian and Luna resolve years of misunderstandings. Luna is crowned queen, and they fulfill their childhood vow on the moonlit terrace.