Kinro is a muscular young man of slightly above-average height with brown hair, green eyes, and a scar on his right cheek. A distinctive long lock of hair hangs between his eyes. He initially wears a sleeveless royal blue uniform resembling a karate gi, secured by a rope belt, and carries a buckler emblazoned with his village's star pattern. After the village tournament, he permanently adopts glasses to correct his nearsightedness. Later, he wears modern clothing crafted by Yuzuriha when she establishes her fashion store. Born in Ishigami Village, Kinro serves as a guard alongside his younger brother Ginro. He rigidly adheres to rules, epitomized by his personal motto: "Rules are rules." This leads him to initially block Senku and Kohaku from entering the village, citing security protocols despite Senku having saved Kohaku. Skeptical of Senku's "sorcery," he refuses ramen or suspicious activities but accepts a gilded spearhead, developing a fierce attachment to it. He hides his nearsightedness, viewing it as an excuse for failure. Kinro joins the village tournament to help Kohaku save her sister Ruri. During his fight against Magma, impaired vision hinders him until Suika provides her lens-equipped watermelon helmet, enabling him to overpower his opponent. After winning, he demands verification of the lenses' legality per village rules. When Senku secures chief status, Kinro publicly vouches for his integrity, signaling growing trust, and later persuades the village to allow Senku's attempt to cure Ruri. During Hyoga's raid, Kinro guards a critical bridge. Severely wounded battling Hyoga, he orders Ginro to destroy the bridge even if it kills him—a command Ginro refuses. Treated with Senku's medicines, Kinro returns to duty prematurely, showcasing his dedication. He soon receives permanent glasses, eliminating his vision handicap, and wields a Senku-crafted katana to help repel Hyoga's forces. As the Kingdom of Science expands, Kinro contributes to projects like the hand-cranked generator, resenting the labor until automation relieves him. He aids in creating currency ("dragos") and shows enthusiasm for inventions like the automobile. His loyalty solidifies; he joins Senku's literacy school, recognizing writing's importance despite initially dismissing it as impractical for combat. He demonstrates protectiveness by kicking Suika to safety before his petrification during the Treasure Island expedition. On Treasure Island, Kirisame petrifies Kinro. After Suika retrieves and revives his statue, he praises her growth. Using new diving gear, he assists in locating submerged petrified allies and witnesses Taiju retrieving statues without oxygen. Kinro later joins the decisive tug-of-war against Ibara, strategically leveraging the petrification device to secure victory.