The heroine has the ability to see through living things and knows everything about people. He was poached by the King of Hell to become the Ghost Judge of the underworld. He was forced to reincarnate because he didn't understand human feelings. After several lives, there is no love, just like a marionette. The male protagonist was originally a puppet, but was later transformed into a human form by the female protagonist's blood, and joined the demon-killing team.
Purpose: Slowly understand one's mission