A regretful story belonging to An Shiyin and Ning Shen.
After Ning Shen left, An Shiyin waited for the arrival of spring alone, but her spring left with Ning Shen, and all her memories stayed in that winter that could not be said to be cold, and in the last letter Ning Shen sent.
The fictional background is all made up. Any similarity is purely coincidental.
Purpose: cherish the present moment