After being dumped by his girlfriend, emotionally shattered college student Kazuya Kinoshita tries to fill the void in his heart by renting a girlfriend through a mobile app. Initially, Chizuru Mizuhara appears to be the perfect girl, possessing everything he could possibly want: great looks and a cute, caring personality. After seeing mixed opinions on her profile following their first date, and still tormented by his previous relationship, Kazuya assumes Chizuru is merely playing with men's hearts and leaves her a negative rating. Angry at her client's disrespect, Chizuru reveals her true nature: sassy and temperamental, the complete opposite of Kazuya's first impression. At that very moment, Kazuya receives news of his grandmother's collapse and is forced to bring Chizuru with him to the hospital. Although it turns out to be nothing serious, his grandmother is ecstatic that Kazuya has finally found a serious girlfriend, which had always been her wish. Unable to tell her the truth, Kazuya and Chizuru are forced into a fake relationship—acting as if they are truly lovers.