Phantom the Secret Agent

"A romantic drama that focuses on the love stories of high school best friends Min Joo, Kang Chan, Bang Hee, and Hyun Beom. Everything begins when Min Joo, who develops an unrequited love for Kang Chan for a long time ends up having her deceased brother Dae Yeon’s soul take control of her body. To fulfill his younger sister’s one-sided love, Dae Yeon does his best to win over Kang Chan’s heart."