With the highest kaiju-emergence rates in the world, Japan is no stranger to attack by deadly monsters. Enter the Japan Defense Force, a military organization tasked with the neutralization of kaiju. Kafka Hibino, a kaiju-corpse cleanup man, has always dreamed of joining the force. But when he gets another shot at achieving his childhood dream, he undergoes an unexpected transformation. How can he fight kaiju now that he's become one himself?!

The Defense Force has taken Kafka into custody and plans to dispose of him. To save himself, Kafka attempts to plead his humanity to Director General Shinomiya, wielder of the mighty Kaiju No. 2's power and the person lauded as the strongest in Defense Force history. When Kafka's pleas fail to move the director general, he winds up facing him in combat! Can Kafka keep his kaiju form together long enough to save his own skin?