Natalie, a child in the Quinn family, had a difficult life. Her mother constantly taunted and bullied her, while her sister tried to take everything she had, including her boyfriend. However, the most pressing issue was the medical expenses of her foster mother Hannah, the only person who had shown Natalie kindness throughout her life and had raised her since childhood. The Quinn family agreed to cover Hannah’s medical expenses, but only if Natalie agreed to marry Sebastian, the illegitimate and good-for-nothing son of the wealthy Klein family, and replace her sister as his spouse. After getting married, both Natalie and Sebastian discovered that their partner was keeping something important from them.