Seong Sumin is the team manager of Hello Studio, a company that develops mobile games and is run by her ex-girlfriend, Baek Seju. Sumin is struggling to get over her painful past by jumping from one partner to another, but at the end of the day, she always ends up going back to Seju, who likewise does everything in her power to make sure that Sumin belongs only to her.

When young, beautiful Ju Seongji joins the company, she instantly captures everyone's attention, including that of the team leader. Sumin's life is changed forever after meeting Seongji, and with Seju always looking over her shoulder to make sure nobody steals her heart, a unique and complicated love triangle forms. What Does the Fox Say? follows the life of the three women and the drama that unfolds as their relationships intertwine together.