Once a famous actress, the vampire Im Sooyi fell in love with a human, Cha Seunghyun, and left the public eye to raise their three boys: Jisung, Yusung, and Hyesung. Now 29 years old, Jisung is in a loving relationship with his coworker Kang Yeri, and he never craves blood. The handsome 27-year-old Yusung can consume both human food and blood, but he has yet to abandon his womanizing ways and form a meaningful bond with someone. Meanwhile, the cheeky 17-year-old Hyesung survives only on blood, which has led to some unproductive homeschooling. As Jisung and Yeri hide their office romance, Yusung meets a woman immune to his charms, and even Hyesung has a fateful encounter with a girl who gives him butterflies. Sooyi may be an adoringly attentive mother who likes to meddle, but there is no greater joy than witnessing her sons discover the ultimate secret to overcoming their thirst for blood—love. [Written by MAL Rewrite]