Tokyo in 2017 overlaps with Aichi in 1984. The suspect has confessed to the crimes committed many years ago, but his confession leads everyone into a deeper maze. The murderer's son and the deceased's daughter both had doubts about the police's conclusions, so they secretly joined forces to investigate, and step by step uncover the secrets that their parents had concealed throughout their lives. Good and evil, right and wrong, crime and punishment, logic and sensibility... All the seemingly opposite and incompatible things reversed their positions in front of the huge gear of fate, reversed yin and yang, and finally merged into one.