Isa is part of ancient
Satsuma Province and was part of the holdings of
Satsuma Domain in the
Edo period. On April 1, 1889, the villages of Oguchi, Yamano, and Hazuki were established with the creation of the modern municipalities system. Oguchi was raised to town status in 1918, followed by Yamano in 1940. In 1954, Oguchi, Yamano, Hazuki, and Nishitara village in Isa District were merged to form the city of Oguchi. Likewise, the villages of Hishikari and Tara were established on April 1, 1889 with the creation of the modern municipalities system. In 1891, Tara was divided into Higashitara and Nishitara, and in 1925 Higashitara was renamed Honjo. In 1940, Hishikari was raised to town status, and in 1954, Hishikari annexed Honjo. The city of Isa was created on November 1, 2008, from the merger of the city of
Ōkuchi, and the town of
Hishikari (from
Isa District). Isa District was dissolved as a result of this merger. ==Government==