Kinro is a young man from Ishigami Village, the son of Tetsuken and Shirogane and the elder brother of Ginro. He and his brother served as village guards, a role he approached with unwavering seriousness due to his firm dedication to rules and order. He possesses a muscular build and stands slightly above average height, with brown hair, green eyes, and a scar on his right cheek. A distinct long lock of hair hangs between his eyes. For much of his early life, his face bore a frequent scowl, partly due to significant nearsightedness that he concealed, referring to it as "blurry eye disease." His standard attire was a sleeveless royal blue karate gi-like uniform with a rope belt and a buckler displaying the village's star pattern on his back. After the village tournament, he began wearing glasses to correct his vision and later carried a katana following Hyoga's raid. He also adopted modern clothing after a fashion store was built. Stern, rule-abiding, and principled, Kinro believes deeply in hard work and despises laziness or cheating, even for noble causes. He alone opposed rigging the village games to help the Kingdom of Science win, despite the aim of curing Ruri. He initially barred Senku from the village even after Senku saved Kohaku’s life and rejected involvement in what he considered sorcery, refusing to try Senku’s food—though he accepted a gilded spearhead, to which he grew deeply attached. Despite his rigidity, he is not prejudiced and can recognize goodness in others, eventually becoming a loyal member of the Kingdom of Science and vouching for Senku’s character to the village. He demonstrates fierce loyalty to his friends and dedication to protecting others, willing to sacrifice himself by having his brother cut a bridge while he remained on it with enemies. Prideful, he never used his poor eyesight to excuse failure. Although typically stoic and serious, he can show emotion and excitement, such as his enthusiasm for an automobile and a generator that eased his labor. His reasoning was initially weak—he refused to believe in life beyond the village—but he learned to overcome stubbornness, joined Senku’s literacy school, and acknowledged writing’s importance for communication. His abilities are combat-focused. He is a skilled spearman and later showed high proficiency with a katana. With enhanced physical prowess, he ranks among the strongest in Ishigami Village, rivaled only by Magma and Kohaku. His considerable strength and stamina allowed him to overpower Magma once his vision was corrected and to operate a hand-powered generator for long periods. Initially, severe nearsightedness hampered his combat effectiveness, leading him to sharpen his other senses. After receiving glasses, his capabilities improved dramatically. His history and development unfold through events in Ishigami Village and his interactions with the Kingdom of Science. He first appeared blocking Kohaku and Senku from village entry. Eventually bribed with a gilded spearhead to allow passage, he claimed it would not secure his loyalty. His spear was destroyed when Kohaku used it as a lightning rod. Manipulated by Gen Asagiri into powering a generator with the promise of spear repair, he agreed to help Kohaku win the village games to save Ruri and trained for the competition. During his match against Magma, his impaired vision put him at a disadvantage until Suika provided her helmet with corrective lenses made by Senku. With temporary vision correction, he defeated Magma but was knocked out by a surprise attack. After Senku won the position of village chief, Kinro vouched for his character, citing observed resolve and belief in him. When Hyoga and the Tsukasa Empire attacked, Kinro was seriously injured defending the bridge but insisted on returning to guard duty the next day. He received glasses for permanent eyesight correction and medicine for his injuries. He fought Hyoga again in the second attack using a katana and helped protect villagers during the battle. As a Kingdom of Science member, he engaged in endeavors like operating generators and learning to write, demonstrating adaptation to new scientific methods and ongoing dedication to his duties.