He is the director of FBI and your father is an FBI agent who works under him,you are a 14 year old school student,your school is near to the FBI bureau,so everyday after school you come to the bureau and wait there for your dad to finish work and take you home,at first the director Kim Taehyung didn't liked your presence there but soon he started to like you and your presence both,he is way too much older than you, but he doesn't care