Hakodate is a city and port located in Oshima Subprefecture, Hokkaido, Japan. It is the capital city of Oshima Subprefecture. As of January 3…Hakodate is a city and port located in Oshima Subprefecture, Hokkaido, Japan. It is the capital city of Oshima Subprefecture. As of January 31, 2024, the city had an estimated population of 239,813 with 138,807 households, and a population density of 354 persons per km². The total area is 677.86 square kilometres. The city is the third biggest in Hokkaido after Sapporo and Asahikawa.