Gao Dumei (Park Shin Hye) is an editor who has been staying at home for many years. Because of the trauma she suffered in her childhood, Dumei has closed herself off. The days passed by so uneventfully until Dumei began to notice that person. That person, Han Taejun (Kim Jungsan), is a doctor and Dumei's neighbor. Dumei's greatest pleasure every day is to peek at Taejun and fantasize about the good days with Taejun. This kind of life was completely destroyed by Taejun's cousin Enrique Kim (Yoon Shi-yoon) who returned from Spain. Enrique Kim is a super game designer with dual citizenship. Dumei's peeping behavior was discovered by him, which made Dumei feel embarrassed. The two got to know each other in this bad impression, and a series of stories about neighbors unfolded... This drama is the third part of the Flower Boy trilogy. The first two parts were "Shut Up! Flower Boy Band" and "Flower Boy Ramen Shop".