Seong Sumin is Hello Studio's team manager. It's a mobile games company run by her ex-girlfriend Baek Seju. Sumin tries hard to get over her traumatic past by moving from one partner to another, but she still ends up returning to Seju at the end of the day, who always does everything in her power to make sure that Sumin belongs to her only.
When a young and beautiful Ju Seongji enters the company, she instantly captures everybody's attention including the team manager. After meeting Seongji, Sumin's life changes forever. Seju always looking over her shoulder to ensure no one steals her heart, a unique and complicated love triangle between three women forms.