Mizuki Aoshima (Shota Watanabe) works for a beverage manufacturer. He is handsome, sociable, and does his job well. He is popular among the female employees at his company, however, he is not good at interacting deeply with people and he doesn't have interest in having a romantic relationship. So far, he hasn't had a girlfriend. One day, he happens to sit next to Yukino Katsuragi (Anne Nakamura) at an izakaya. She who works in a different department at the same beverage company where Mizuki Aoshima works. Yukino Katsuragi is 35 years old and has been single for about 6 months. She has a strong sense of responsibility and she doesn't mind doing other employees' work when necessary. She has a mindset that being alone is more important than love and it's annoying that her life is disrupted by love. In reality, she just doesn't want to get hurt in a relationship. Her friend calls and she remembers that she promised to attend her friend's wedding with her boyfriend whom she is no longer seeing. After she meets Mizuki Aoshima, she asks him to pretend to be her boyfriend for one day.