A professional woman leaves her dental practice in Seoul and moves to a seaside village. There she meets a local resident who is unemployed but seems to do everything around town, from helping those in need to being a part of everyone's life. The two become interested in each other despite their differences.
Love Alarm is an app that tells you if someone within a 10-meter radius has a crush on you. It quickly becomes a social phenomenon. While everyone talks about it and uses it to test their love and popularity, Jojo is one of the few people who have yet to download the app. However, she soon faces a love triangle situation between Sun-oh whom she starts to have feelings for, and Hye-young, who has had a huge crush on her.