TV-Series
Description
Kafka Hibino is a 32-year-old man who serves as the protagonist. He was born on August 5 and stands 181 centimeters tall. Prior to his current occupation, he worked as a kaiju corpse disposal specialist for a company called Monster Sweeper Inc.. His life is defined by a childhood promise made with his friend Mina Ashiro after a kaiju attack destroyed their hometown; together, they vowed to join the Defense Force and eradicate kaiju. While Mina succeeded and eventually became captain of the Third Division, Kafka repeatedly failed the entrance exams and resigned himself to a career in kaiju cleanup, believing his dream was over due to the age limit of 32.

In terms of personality, Kafka is characterized by a strong sense of responsibility and a kind-hearted, caring nature. He demonstrates bravery, often acting selflessly to protect others even at great personal risk, though this can manifest as a disregard for his own safety. He is described as friendly and approachable, which helps him get along easily with younger colleagues despite being the oldest among new recruits. He has a comically childish side and becomes annoyed when referred to as an old man, but in serious situations, he is a dedicated and determined individual who tries his best for the group.

Kafka Hibino's primary motivation is to fulfill the childhood promise he made to Mina Ashiro to stand beside her and fight kaiju. After meeting his junior colleague Reno Ichikawa, who reignites his passion, Kafka decides to take the Defense Force exam one last time. His transformation occurs when a mysterious small kaiju appears and enters his mouth, granting him the ability to transform into a powerful humanoid kaiju while retaining his human consciousness.

His role in the story is that of a protagonist with a dual identity. He joins the Defense Force while concealing his kaiju nature, becoming a cadet in the Third Division. Despite his immense power in kaiju form, his combat suit release rate as a human is exceptionally low, starting at 0% and later improving to only 1%, which puts him at a significant physical disadvantage compared to other recruits. He compensates for this with his extensive knowledge of kaiju anatomy gained from his years in disposal work, which allows him to provide crucial tactical support during missions.

Key relationships define much of his journey. Mina Ashiro is his childhood friend and the captain of the Third Division, representing the unfulfilled dream he hopes to achieve. Reno Ichikawa is his trusted friend and confidant, the first to witness his transformation and the one who supports his secret. Within the Defense Force, Vice-Captain Soshiro Hoshina becomes an important figure who recruits Kafka as a cadet and later acknowledges his contributions. Kikoru Shinomiya is a fellow cadet whom Kafka saves during a mission, leading to a bond of mutual respect.

Kafka's character development centers on his acceptance of his dual nature as both a human and a kaiju. Initially fearful of being discovered, he gradually learns to use his powers to protect others, though he struggles with the fear of losing control and hurting his comrades. He experiences moments where the kaiju form overwhelms him, leading to a berserk state, but he works to control this aspect of his power. Over time, repeated transformations cause his body to retain permanent kaiju features, such as on his hand, raising questions about his long-term humanity. He eventually reveals his identity to the Third Division to save others, leading to a decision by the Defense Force to use him as a living weapon rather than executing him.

Notable abilities in his kaiju form include immense superhuman strength capable of annihilating large kaiju with a single punch, enhanced speed and reflexes, high durability, and a regenerative healing factor. His kaiju form is classified with a fortitude level of 9.8, one of the highest recorded, which rivals legendary daikaiju. He also possesses a unique kaiju detection ability, allowing him to sense other kaiju and warn allies of impending attacks. He can perform partial transformations, altering specific body parts without fully changing into his kaiju form. However, his powers come with drawbacks; the longer he remains transformed, the more his human body converts into kaiju tissue, risking permanent transformation. Additionally, his own human body can be damaged by the full force of his kaiju blows due to his age and physical condition.