Why Are Mountains and Seas Considered Old Friends?

In the future, the earth is on the verge of decline. Shen Yan, a returnee, carries a mysterious mountain and sea box and enters the world of mountains and seas where the gods abdicate and alien beasts transform into humans. Here, he met Suisui, the nine-tailed fox who had been waiting for thousands of years, Jingwei, who filled the sea with rocks in his mouth day after day, the female demon who was feared by all living beings, and Xiheng, who had taken on the name of god. They all once loved a dead person, but in Shen Yan's body, the memories of those old friends were sleeping: the smell of an old bowl of soup, the origin of a scar, an unfinished farewell, and even the smallest heartbeat when he fell in love with them. The old friend seems to have returned, but he is not returning after all. When the mountains, seas and future collapse at the same time, Shen Yan must choose between saving the world and preserving himself; four women who have spanned a long time must also answer again: Is the person they love the dead in their memory or the similar but independent person in front of them? Love is originally very simple - just wanting to eat, quarrel, and stay with someone until they get home safely. But death, time, the name of God, and past lives have made this simple thing out of reach. This is a meeting across mountains and seas and the future, and it is also a sentence written to all old friends: the past life cannot replace the present, and the same memory cannot prove the same soul. There may be similar flowers in the world, but no one can complete its life in place of another.