was a town located in Nishisonogi District, Nagasaki Prefecture, Japan.
As of 2003, the town had an estimated population of 7,577 and a density of 96.25 persons per km<sup>2</sup>. The total area was 78.72 km<sup>2</sup>.
On April 1, 2005, Ã Âseto, along with the towns of Saikai (former), Ã Âshima, Sakito and Seihi (all from Nishisonogi District), was merged to create the city of Saikai.