[4] Per Japanese census data,[5] the population of Komoro peaked at around the year 2000 and has declined slightly since.

The Tōsandō, one of the national routes passed Komoro, which was the location of an Umaya (駅), or post station for government officials and army.

In those days, Komoro Tarō Mitsukane (小諸太郎光兼), a gokenin, was assigned by the shogunate to govern the area.

The town of Komoro annexed villages of Kawabe, Kitaoi and Osato (all from Kitasaku District) on February 1, 1954.

The city of Komoro was established on April 1, 1954 after absorbing the villages of Minamioi and Mitsuoka (both from Kitasaku District).

Komoro has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 19 members.

Komoro is a regional commercial center and has a primarily agricultural economy based on cultivation of rice, vegetables and fruits.