Kenji Miyazawa hails from Ihatovo, a rural farming village in Japan's Tōhoku region. Raised without electricity, telephones, or knowledge of money, he herded cows with his family under a motto advocating firmness against defiant livestock. A catastrophic storm once obliterated the village's decade-old orchard, forcing residents to replant seedlings from scratch. Years later, during a devastating 50-year landslide, he single-handedly reshaped a mountainside to divert floodwaters and save Ihatovo—though his best friend perished, an event Kenji insists he cannot recall. This feat attracted Yukichi Fukuzawa, who recruited him into the Armed Detective Agency. Kenji greets everyone with unwavering friendliness and optimism, earning renown for his hospitable nature. His rural roots foster naivety toward urban norms, leading to unconventional tactics like bluntly asking suspects about crimes and trusting their denials. Yet he harbors a menacing side when provoked or defending friends, shifting into aggressive determination. He staunchly believes sincerity toward others—even animals or unfamiliar challenges—always elicits reciprocal sincerity. His ability, "Undefeated by the Rain," grants superhuman strength and durability, enabling him to lift massive weights, flip vehicles, and resist bullets. This power activates solely when his stomach is empty; eating triggers immediate deep sleep. The ability’s name and ethos derive from a poem by his real-world namesake, championing resilience through adversity. Within the Armed Detective Agency, Kenji aids critical missions. He repelled Port Mafia assaults on headquarters and investigated a car bombing with Atsushi Nakajima, using his interrogation style and combat skills to dismantle a fertilizer-smuggling gang. During the Guild arc, he endured brief imprisonment in an alternate dimension before its collapse freed him. He later defended the agency against Port Mafia and Guild incursions, demonstrating fierce loyalty to Fukuzawa. In the Cannibalism arc, he evacuated the hospitalized president and stormed Port Mafia headquarters. Learning of Atsushi’s torture in the Hunting Dogs arc unleashed his menacing side; he battled Ochi Fukuchi and sustained grave injuries while fiercely confronting the Hunting Dogs. His family’s motto of practical resolve and the literary legacy of his namesake—emphasizing perseverance and harmony with nature—subtly shape his character. Trivia notes identify him as one of the agency’s youngest members, typically clad in rural attire: blue overalls, a beige shirt, and a straw hat.