Komakai-juku was the next station after Kuronoda-shuku when traveling from Edo, and located at the foot of the mountain via Sasako Pass, which was thought to be the most dangerous section on the old Koshu-kaido Road. It is said that this post station was the location of the Imperial Ranch in the Kai Region with one main lodging (honjin), two sub-lodgings (waki-honjin) and six inns (hatago). Residents of the town continue calling one another by their trade names, which is one of the influences from that time.
Komakai-juku and Tsuruse-juku, the next station to the west, opened by turns. This style of operation by two post stations was called aishuku.