Uto is a city located in Kumamoto Prefecture, Japan. As of 31 July 2024, the city had an estimated population of 36,149 in 16127 households, …Uto is a city located in Kumamoto Prefecture, Japan. As of 31 July 2024, the city had an estimated population of 36,149 in 16127 households, and a population density of 490 persons per km². The total area of the city is 74.30 km².