Trouble G트러블G

Jin-Hung has an unusual power. She can see ghosts and make them disappear with a single word!. One day, walking through the streets, she sees a guy about to get hit by a car. Jin-Hung runs to him to help him only to discover he was a ghost! But he was not an average ghost, he was Shin-Yi, her first crush from middle school. Shin-Yi starts to follow Jin-Hung to school, and later.. another ghost, Yi-Ryeong appears! Apparently, he's Shin-Yi's best friend. How did they end up dead?..And.. why does Yi-Ryeong suddenly start to follow Jin-Hung claiming to be her guardian?