Monstrous creatures known as "kaijuu" have been terrorizing Japan for decades. To safeguard the population, an elite military unit called Defense Corps puts their lives on the line every day. When one of these beasts is slain, professionals from the Professional Kaijuu Cleaner Corporation are tasked with disposing of its remains. Kafka Hibino, a 32-year-old man, has long been unhappy with his job as a sweeper and yearns to join Defense Corps in order to kill kaijuus for a living. Despite several failed attempts, he eventually resigned himself to the mediocrity that provided a decent income. However, when an ambitious new recruit named Leno Ichikawa joins his cleaning team, Kafka is reminded of his dream once again. Unfortunately, after a series of unfortunate events and an encounter with the junior sweeper, Kafka becomes infected by a parasite-like kaijuu that forces its way into his mouth, transforming him into a humanoid monster. With newfound powers, Kafka decides to give his lifelong dream one final shot.
Episodes 1-2 were previewed at theatrical screening in Japan on March 31, 2024. Regular broadcasting began on April 13, 2024.