In this world, human emotional changes are very important. When a person's emotions continue to be in a negative state, evil spirits will emerge; they feed off the negative emotions of the "host" and gain powerful power, leading to endless disasters. For this reason, official organizations have been established around the world and "investigators" have been dispatched to deal with sudden evil spirits incidents in various places. However, there are many unknown secrets behind the official symbol of justice... Pure righteousness is evil, and pure evil is also righteousness.
