The story takes place in a bustling American city and tells the angsty yet sweet love story between elite scholar Serena and Leo, the Wolf King of North America. Six years ago, Serena, an Ivy League student, was framed out of jealousy by Vivian. She accidentally saved Leo, who was in heat, in a church and was forced to mate with him. Because she gave birth to a son, Liam, who bore wolf-like traits, she was expelled from school and plunged to the bottom of society. Six years later, in order to raise $150,000 for her son's surgery, Serena applied to become Leo's personal nutritionist. Although Vivian kept interfering and tampered with the paternity test report, the bond of blood compelled Leo to fiercely protect his own without even realizing it. After crushing workplace bullying and threats from old enemies, the truth about the fake report came to light, and the family of three was reunited. Meanwhile, a hidden vampire crisis quietly began to unfold.