The line was originally planned by Kominato Railway, which obtained the government license for the new line between Hon-Chiba Station in central Chiba and Amaariki Station on the existing Kominato Railway Line in December 1957.

Following years of suspension of the project, in December 1975, the license was transferred to Chiba Kyūkō Dentetsu (千葉急行電鉄), which was jointly established by Keisei Electric Railway and the Kominato Railway receiving investment from local governments and other sources.

By the 1970s, the need for the railway had been increasing as the development of Chiba Ichihara New Town was in progress along the planned route.

The plan was changed to make connection with the Keisei Chiba Line at Chiba-Chūō Station.

The entire line is single track, but the formation allows for duplication if and when required.