Omitama is a city located in Ibaraki Prefecture, Japan. As of 1 July 2020, the city had an estimated population of 48,776 in 18,311 households …Omitama is a city located in Ibaraki Prefecture, Japan. As of 1 July 2020, the city had an estimated population of 48,776 in 18,311 households and a population density of 337 persons per km². The percentage of the population aged over 65 was 30.0%. The total area of the city is 144.74 square kilometres.