The story of the Seven Deadly Sins, a group of warriors who were wrongly accused of a crime they didn't commit and went on a quest to vindicate themselves.

Anna, a shy 12-year-old girl, is sent to spend time with her aunt and uncle who live in the countryside, where she meets Marnie. The two become best friends. But Anna gradually discovers that Marnie is not quite who she appears to be.

The humanity is suffering from murders all over the globe, called "Mincemeat murders". High school student, Izumi Shinichi has a parasite living off him, having replaced his right hand, and he might be the discoverer of truth.