In the future city "Xingang" where memories can be extracted and traded, Lin Chen, a top memory weaver, makes a living by repairing and erasing other people's memories, but he is troubled by a blank memory about his missing sister. A mysterious commission brought him a memory crystal ball that only recorded half of a lullaby, and that melody was his only clue to finding his sister. In order to pursue the truth, Lin Chen was forced to sneak into the gray area of memory and start a game with the "Hall of Eternal Life", a mysterious organization that manipulates memory. He must navigate among other people's memory fragments, piece together the forgotten past, and at the same time be careful not to be swallowed by this vast "sea of forgetfulness", and finally find the "island of memory" that belongs to him.
