Hachikai, Aichi
[file:Aisai-city City Office Hachikai Branch 20131011.JPG|thumb|right|former Hachikai List of villages in Japan|village hall]
Hachikai was a village located in Ama District, Aichi Prefecture, Japan.
As of 2003, the village had an estimated population of 4,930 and a density of 404.43 persons per km2. The total area was 12.19 km2.
On April 1, 2005, Hachikai, along with the towns of Saya and Saori, and the village of Tatsuta, was merged to create the city Aisai.