Humans at afraid of being eaten. They're weak compared to monsters. They obey all orders, or face being eaten. Ivan is a human who hates monsters and wants to kill them all. Deep down he's afraid but wants to remain strong for his people. This world is ruled by monsters, who use humans as their main source of meat. There's a group that fights to break humans out of farms to save them from being eaten, Ivan was once a leader in that.