With vague memories, the vigorous boy Ke Moqi spent a good (fog) time with the mouthless boy Iku and a certain scumbag. After escaping the pursuit of the mysterious organization, Mo Qi found that he had arrived at the place in his memory by accident (heavy fog). Finally, he realized that some details could not match his memory, but when Mo Qi explored the truth, he discovered that he was not a normal person. Facing the cruel truth and Iku's long journey of pursuit, where will Moqi go...