This is a thriller and mysterious drama about youth. A 17-year-old girl named Huang Shu was killed in 2013. But the method of murder was not known. About ten years later a similar case happened. The suspect of the first case was dead and the case was closed. This drama will dig into the life of five boys and girls. The incidents were due to human complexity. The bad intentions of children were clear. So, is it true that you and I were both sinners?