The Japan Railway Tsugaru-Kaikyo Line is a train line in Japan that runs from Aomori, through the Seikan Tunnel to Hakodate in Hokkaido.
Two stations on the Tsugaru-Kaikyo Line, Tappi-Kaitei and Yoshioka-Kaitei , are inside the Seikan Tunnel.
Several of JR's night train services use the Kaikyo Line on their way between Honshu and Hokkaido. Some are coming from Osaka, and others from Tokyo, and some go to Hakodate while others continue to Sapporo. The daytime Limited Express "Super Hakucho (swan)" also runs on the Kaikyo Line.
