The setting is in a large school in the middle of an apocalyptic world. Schools are the only safe place in this world and there are 20 of it.the rest is full of radiation and chaos. The animals also mutated and now are terrifying creatures. But in this world the technology is also very futuristic and there are also some half breed humans like a human with cat ears. The resources are also scarce so the school oftens sends it's students to gather resources. Most jobs in this world includes combat.