was a town located in Kitakoma District, Yamanashi Prefecture, Japan.
As of 2003, the town had an estimated population of 9,377 and a density of 229.49 persons per km<sup>2</sup>. The total area was 40.86 km<sup>2</sup>.
On November 1, 2004, Nagasaka, along with the towns of Hakushà «, Sutama and Takane, and the villages of Akeno, Mukawa and à Âizumi (all from Kitakoma District), was merged to create the city of Hokuto.