Kuroiso (黒磯市; -shi) was a city located in Tochigi, Japan. On January 12005, the city was merged with the towns of Nishinasuno and Shiobara to form Nasushiobara city. In 2003, the city had an estimated population of 60,145 and the density of 175.29 persons per km². The total area was 343.12 km². The city was founded on November 1, 1970. Source: [wikipedia: kuroiso, tochigi]