The double-track line is situated below Kawabata Street, along the left (eastern) bank of the Kamo River.

It is constructed under Kawabata Street along the Kamo River as an underground extension of the Keihan Main Line.

The line is only 2.3 km (1.4 mi) long but serves as an important transport corridor in central Kyoto.

April 10, 1950: Keihan Electric Railway established the Ōtō Line Construction Preparation Committee.

The timetable revision accompanying this has been carried out ahead of September 27, until noon October 5 was operated as a forwarding train in the Ōtō Line.