It is a unique buddy drama about a young university student and a mysterious homeless person bonding through their struggles and experiences with unfulfilled past loves.
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.
With the aid of unexpected friends, a gifted but introverted student confronts bullies and violent foes — unaware of how dangerous his world will become.