As of November 1, 2007, (the last census information available) the town had an estimated population of 22,708 and a population density of 2,188.31 persons per km2. The total area was 9.92 km2.
On February 1, 2010, Kozakai was merged into the expanded city of Toyokawa. Therefore, Hoi District was dissolved as a result of this merger.
History
October 1, 1889 – Toyoaki Village (豊秋村) was founded.
September 12, 1906 – Kozakai Village was founded by the unification of Toyoaki Village and Ina Village (伊奈村).