在日本有一个专门的机构，名字叫做非自然死亡原因研究所。他们在平时的工作只有一个，那就是专门研究一些看似正常，但其实是非自然死亡的一些事件

故事的主人公是研究所当中的一员，三澄美琴极具正义感，许多人员的非自然死亡都被归结到了医疗失误或者是一些未知的疑难疾病等等。但在这些事件的背后都隐藏着一个变态杀手，许多被归结为非自然原因死亡的都没经历解剖直接被火化，这样所有的证据就全部消失了，凶手也可以逍遥法外。三澄美琴和他的同事们想要改变这个现象难度是非常高的，首先需要说服的是被害者的家属，他们是否同意对死者进行解剖，这是一个非常大的难题。其次在法律文献方面，他们面临的挑战是非常多。

There is a special institution in Japan called the Institute of Unnatural Causes of Death. They have only one job in normal times, and that is to specialize in some seemingly normal, but actually unnatural deaths

The protagonist of the story is a member of the research institute. It comes down to medical errors or some unknown difficult diseases and so on. But there is a perverted killer hidden behind these incidents. Many people who were attributed to unnatural causes of death were directly cremated without undergoing an autopsy, so that all the evidence will disappear and the murderer can get away with it. It is very difficult for Sansumi Mikoto and his colleagues to change this phenomenon. The family members of the victim need to be persuaded first. Whether they agree to the autopsy of the deceased is a very big problem. Secondly, in terms of legal literature, they face many challenges.