The misty forest under the doomsday wasteland, the friendly elves (?) Met on the journey, the meeting between the spiritual world and the human world is on an island? Is the "elf spring water" of immortality really the spring water of immortality? The intertwined relationships, the truth about lost memory, is there a chilling conspiracy behind the fog or a forced choice? Will you still be my friend at the end of the world?
Concept: What the eyes see may not be the truth, it may be fog