The line was originally built by the Ehime Railway (愛媛鉄道, Ehime Tetsudō) as a 762 mm (2 ft 6 in) light railway line from Wakamiya Junction (若宮連絡所, Wakamiya-renraku-sho), near Nagahama-machi (the present Iyo-Nagahama) to Uchiko, opening on May 1, 1920.

[1] On November 25, 1985, the line was closed and the passenger service was replaced by buses to allow heavier rails to be laid, the railbed to be strengthened, and curves to be relaxed.

The next year, on March 3, the upgraded line between Uchiko and a point 2.5 km west of Niiya (with new passing facilities at Niiya and relocated stations at Uchiko and Ikazaki), together with new sections of the Yosan Main Line from Mukaibara to Uchiko and the point 2.5 km west of Niiya to a new junction 2.5 km east of Iyo-Ōzu, with Centralised Traffic Control along all sections, opened as a shortcut route between Matsuyama and Uwajima.

The curve section from the point 2.5 km west of Niiya to the junction at Gorō was closed.

JR Freight subsequently ceased to run services on the line on April 1, 2006.