In Japan, monsters known as kaiju regularly attack the populace with the Japanese Defense Force tasked with killing them. After their town was destroyed by kaiju when they were children, childhood friends Kafka Hibino and Mina Ashiro both vowed to become members of the Defense Force. Mina has become famous as commander of the Defense Force's Third Unit, but Kafka has failed the examination numerous times and is a member of the clean up crew, Monster Sweeper Inc., whose job is to dispose of th...