Ban Dong Wook is suffering from chronic insomnia every night and it gets worse with the bad weather. One day in those painful days, he falls into a deep sleep next to Lee Do Hyun by chance. That’s how Do Hyun, the only shelter for Dong Wook, becomes irreplaceable to Dong Wook. Hanging out together, Do Hyun has a crush on Dong Wook and tries to confess. However, it didn’t go well as planned. Dong Wook only receives a gift not knowing who gave it to him and Do Hyun misunderstood it as he was dumped. Stuck in a misunderstanding, they drift apart. 5 years later, on campus, they met again in the basketball game. However, they still have different feelings about each other. Their relationship, started with first love and ended in misunderstandings, continues again in campus. Will they be able to reconnect their broken ties?