The box is full of Xie Jijing's old things, carrying their common memories of youth that have long since been dusted away. There is no later hatred, no pain, only the bright and flying His Highness the Crown Prince who has not been torn apart by fate.
This is crueler than any last words.
It says silently: I'm leaving. I took away all the hatred and resentment, and also took away the unbearable pain that followed. All that is left to you is the clean "I" from the beginning, the best friend with whom you had a great time drinking and chatting about the world. This is the end between us. All the love, hate, and resentment were completely buried on the top of the snow-capped mountains as I left.
Intention: Loving yourself is the best solution.