Engel lives in a universe where the population consists of humanoid creatures made entirely out of paper, not dissimilar to origami. The aforementioned universe is surprisingly violent, having murder occur very often. Engel is 15 years old, and goes to the rather generically named Paper School. The school is fairly normal, besides the fact that the only 3 teachers are menacing individuals fueled by bloodlust. If a student gets a fail grade, the teachers will kill them without remorse.