Lee Seung-yeon

When the app is launched, a ghost appears. Developed by four young adults, the app becomes the centerpiece of a livestream where they venture into a supposedly haunted mountain to prove its authenticity—only to meet a grim fate.

Da-bin, who dreams of a normal high school life, helps his younger sister Eun-seo, who is deaf in one ear, get to and from school every day. When he learns that his family may have to move far away for Eun-seo, he applies for an exchange program, hoping to take one last trip with his girlfriend. But when he starts working at a motel to cover the costs, he finds himself drifting further away from his plan.

14-year-old Eun-hee moves through life like a hummingbird searching for a taste of sweetness wherever she may find it. Ignored by her parents and abused by her brother, she finds her escape by roaming the neighborhood with her best friend, going on adventures, and exploring young love.

Sang-hoon is a lowlife gangster, a debt collector exercising thuggish ways to collect his money. The recipient of nothing but anger since his childhood, he expresses himself through violence. When he finally encounters someone who can stand up to him, feisty school-girl Yoon-hee they become unlikely friends.