Shanghai, London. 974 Unopened letters.
A mailbox, like a lonely red thread, led the girl who was searching for the cause of her brother's death. After 974 days, she discovered an unimportant truth and a man who was once her brother's lover.
The man, in the fog of London, was exposed the truth that he could no longer avoid. He recalled the old man, the long story and time that he had been in love with for five years and that he would spend the rest of his life in unrequited love. He can slowly move forward with a heart full of scars from his lover, go through the years without him, and go to another beautiful world with him.
Finally, he was ready to board the return flight again and sweep the fallen leaves on his grave.
Go back, go back, let me stay with you for a long time until we meet again.
It is fate that I know you; I love you deeply, and that is my wish.