The was a railway line in northern Japan that linked Aomori Station in Aomori Prefecture and Hakodate Station in Hokkaido.
The Tsugaru-Kaikyō Line was actually made up of portions of four separate lines: the Tsugaru Line, operated by East Japan Railway Company, and the Kaikyō, Esashi, and Hakodate Main lines, operated by Hokkaido Railway Company. The name was created following the opening of the Kaikyō Line and Seikan Tunnel on 13 March 1988.
The line name has been out of use since 26 March 2016 when the Hokkaido Shinkansen opened and replaced the regular passenger services connecting Aomori and Hakodate on the Tsugaru-Kaikyō Line with high-speed services along the shinkansen line. The railway lines that formed the Tsugaru-Kaikyō Line continue to operate freight and passenger trains except for passenger trains on the Kaikyō Line section. The section of line between Naka-Oguni and Kikonai Station ceased operation for conventional line passenger trains like Hakuchō and Super Hakuchō and sleeper trains like Hokutosei, Cassiopeia, Twilight Express and Hamanasu by the 21 March 2015.[1] Today this section is only operated by the Hokkaido Shinkansen, conventional line freight trains and the tourist train Shikishima.