Last year, during her first high school year, Luna dated Jinwoon, and she becomes best friends with B1A4. After they broke up, Jinwoon stopped hanging out with them.. Meanwhile, Nicole, who is LDRing Chunji because Nicole lives at another town where Luna came from too, is going to move to the same high school as Chunji who is a playboy. She met Luna and learns that she is always with B1A4, and she met Jinwoon too. She moves in with Luna who is living with her cousins, BoA and Tae Eun, so she wouldn't have to rent a house. BoA is having LDR too with Chen, Nicole's neighbour back at her town. Soon, she realises that her LDR with Chunji all this time wasn't "Smooth" like what she thinks, or like BoA and Chen's, and Luna's relationship with B1A4, mainly with Sandeul isn't only "Best Friends". Nicole starts to be attracted with Jinwoon and there is Changjo, Chunji's friend from Teen Top, who always tries to be close to Luna.