The lights of the old post office at the end of the alley only come on late at night.
Xu Nian is the person on duty here, sending letters to the past and future for those who have regrets.
Some people send it to their young and cowardly self, some people send it to an old friend who is separated by yin and yang, and some people send it to the person they missed ten years ago.
Letters cannot change the past, but they can make late thoughts arrive well.
Until Chen Xu, the man with the camera on his back, came in the rain to find a reply from six years ago.
He said that that letter contained the regrets of his entire youth.
Xu Nian looked at him, always feeling familiar in his eyes, like a reunion ten years late.
It turns out that all the sorrows in the world have their return date in this post office.
Purpose: To use the cross-time and space post office as a carrier to tell the story of people's reconciliation with regrets and convey the gentle power of "cherishing the present and letting go of the past".