When a teenage ghost starts following her around and making her life a living nightmare, Park Aeri has no choice but to help him fulfill the final dying wish keeping him tied to this world. But fulfilling that wish seems near impossible since it involves her infiltrating the lives of the illustrious and aloof Bulletproof boys. Can Aeri help Taehyung move on to the next life after death? Even if there are still things in this world making him want to stay in it?