In the near-future city "Haicheng" where technology can strip away and seal memories, Ling Su is a "memory diver" who is specially hired to sneak into the "Sea of Forgotten", a chaotic sea of data composed of discarded memories, and salvage forgotten fragments. He is calm and distant, as if he is just a shadow without a past. Until a mysterious woman named Hatsuru appears and entrusts him with retrieving a "color" she has forgotten. This seemingly absurd task dragged Ling Su into a huge whirlpool. He discovered that what Chu Xian lost was not only the color, but also a piece of truth that could subvert the entire Haicheng memory industry, and the core of this truth was actually closely connected with his own blank past. On this island of memory, he must face the abyss of forgetfulness and find the truth that belongs to everyone.
