Kwon Yuri grew up with no parents. She only knew Kwon Jiyong, her twenty years older brother, as her only family left in this world. Things changed when Jiyong dated Sandara Park. At first, Yuri was against their relationship since Sandara was married before and just got divorced. She and her ex-husband had a son, but he lives on his own, and Yuri had never even met him.

Since Jiyong and Sandara were really in love with each other, Yuri realized that she's not in the position to set back their relationship. She gave them her blessings, thus allowing them to get married.

After a year, Yuri decided to live on her own. She's nineteen, already on her first year of college and still has no boyfriend. She thought living alone was a good idea, until one night, a burglar surprised her in her apartment. And he even tries to kill her. Fortunately, the cops were just on time to save her and she only got minor injuries.

After Yuri's traumatic incident, her brother and sister-in-law came up with a solution. She agreed to them in an instant since it's for her own safety. They settled that she will be living with Sandara's son, Choi Minho.

Now everything was in favor for her. Yuri was excited and happy since Minho's house is just minutes away from her university. She arrived at the place, still wondering how her 'nephew-in-law' looks like and how old he really is. She also prepared herself to be a good 'step-aunt'.

When Yuri finally met Minho, an unsuspected plot happened. She was safe, yet always troubled. It feels like she's living in hell, but was happy like she's in heaven. Thus, it was the start of Yuri's twisted life, with her flaming charismatic nephew-in-law, Choi Minho.