Distance didn't keep Choi Junhong and SunHi from being apart. Junhong and SunHi are best friends that, but one day they had to move because of their parents work. They kept talking and little by little they fell in love but still haven't said anything to each other. Choi Junhong is from Seoul and SunHi is from Busan. For these two young teens the first day of every seasons was their best day ever because the first day of every season they meet up in different places and the rest of the seasons they talk to each other on the phone, sometimes they decided to sent each other post cards because they thought it was fun, so every week they received letter from each other.

One day a horrible tragedy happen to Junhong, making him lost all of the memories he had of her. Now she needs to make Junhong remember even if she needs to travel to his two to make him remember.