The only exception to this was the section of the Tōhoku Main Line between Noheji Station and Nishichibiki Station that was shared between the company and the Japanese National Railways (later East Japan Railway Company (JR East)).

The Nanbu Jūkan Railway originally shared the tracks free of charge, but the successor to Japanese National Railways began asking for compensation after that company was re-organized into the various JR companies.

At first, its construction was subsidized by the municipal governments it would pass through, but it was ultimately funded by a steel company based in the city of Mutsu.

The private railway served the area until 5 May 1997 when railbus services stopped because of maintenance costs.

[1] Shichinohe Station (now the headquarters of Nanbu Jūkan Company), some of the track and a railbus are preserved.