Aira is a city located in Kagoshima Prefecture, Japan. It is located west of Kirishima and north of Kagoshima. As of 29 February 2024, the city had an estimated population of 77,948 in 38338 households, and a population density of 340 persons per km². The total area of the city is 231.25 km2 (89.29 sq mi).

Kagoshima Prefecture is a prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,564,175 and has a geographic area of 9,187 km2. Kagoshima Prefecture borders Kumamoto Prefecture to the north and Miyazaki Prefecture to the northeast.