Kuchinawa is an elderly man living in the coal-mining town of Hakoniwa, where he operates a machine repair workshop. He is an eccentric inventor who constantly insists that his work serves the public good, and he fills his shop with a stream of peculiar creations. His personality is outspoken and single-minded, often ranting about his mission to help others, which marks him as a familiar and somewhat quirky figure among the townspeople.

His primary motivation is to use his mechanical expertise to protect the community and uphold what he sees as the common good. This drives him to construct a variety of metallic automatons, including combat-ready machines that eventually take part in defending the town from rampaging mechanical threats. Despite his age, he remains fully committed to his craft and shows no hesitation in deploying his inventions when danger arises.

Within the story, Kuchinawa serves as a supporting presence whose tinkering becomes crucial during the late-stage chaos. His key relationships include interactions with the mapmaker Kagari and her childhood friend Yuya, who are among the locals turning to him for assistance, as well as a quiet granddaughter who sometimes appears by his side. While he does not undergo a dramatic personal transformation, his readiness to act and his arsenal of handmade war machines directly influence the final confrontation. His most notable ability is his ingenuity as a machinist; he is capable of designing, building, and fielding a small army of automata, from walkers to more exotic contraptions, all intended to safeguard the town he has long called home.