In ‘Love Alarm’, a groundbreaking app alerts users if someone nearby has feelings for them, sounding an alarm when within 10 meters. Kim Jo Jo (Kim So Hyun), a smart and attractive high school student, carries a cheerful facade despite the hardships of losing her parents at a young age and living with her challenging aunt’s family. Without a modern phone, she doesn’t use the app. Meanwhile, Hwang Sun Oh (Song Kang), a popular student from a wealthy but emotionally distant family, becomes intrigued by Kim Jo Jo. Noticing his best friend, Lee Hye Yeong (Jung Ga Ram), has feelings for her, Sun Oh impulsively kisses Jo Jo, sparking a complicated love triangle.