Hokkaido Railway Company in the context of "Aomori, Aomori"

The Seikan Tunnel (Japanese: 青函トンネル, Seikan Tonneru or 青函隧道, Seikan Zuidō) is a 53.85-kilometre (33.5-mile) dual-gauge railway tunnel in Japan, with a 23.3-kilometre (14.5-mile) segment running beneath the seabed of the Tsugaru Strait, which separates Aomori Prefecture on Honshu, Japan's main island, from the northern island of Hokkaido. The tunnel's track level lies approximately 100 metres (330 ft) below the seabed and 240 metres (790 ft) below sea level. Following several decades of planning and construction, the tunnel opened on 13 March 1988.

The Seikan Tunnel forms part of the standard-gauge Hokkaido Shinkansen as well as the narrow-gauge Kaikyō Line operated by the Hokkaido Railway Company (JR Hokkaido). Its name, "Seikan," is derived from the on'yomi readings of the first characters of Aomori (青森), the nearest major city in Honshu, and Hakodate (函館), the nearest major city in Hokkaido.

The Hokkaido Shinkansen (北海道新幹線, Hokkaidō Shinkansen) is a Japanese high-speed Shinkansen rail line that links up with the Tōhoku Shinkansen in northern Aomori Prefecture in Honshu and continues on into the interior of Hokkaido through the undersea Seikan Tunnel. Construction started in May 2005; the initial Shin-Aomori to Shin-Hakodate-Hokuto section opened on 26 March 2016. The section of the line to Sapporo was originally scheduled to open by fiscal year 2030, but in December 2024 it was delayed until the end of FY2038, distressing local communities and causing concern over impact on regional development. The line is operated by the Hokkaido Railway Company (JR Hokkaido).

41°22′28.16″N 140°17′13.2″E / 41.3744889°N 140.287000°E / 41.3744889; 140.287000

The Kaikyō Line (海峡線, Kaikyō-sen) is an 87.8 km (54.6 mi) railway line operated mainly by the Hokkaido Railway Company (JR Hokkaido). The line connected Naka-Oguni Station in Sotogahama, Aomori, through the Seikan Tunnel between Honshu and Hokkaido, to Kikonai Station in Kikonai, Hokkaido. Two stations on the Tsugaru-Kaikyō Line, Tappi-Kaitei Station and Yoshioka-Kaitei Station (both closed since 2014), were inside the tunnel.

The Japanese National Railway Settlement Corporation (日本国有鉄道清算事業団, Nihon Kokuyū Tetsudō Seisan Jigyōdan), or JNRSC, was a temporary holding company created to distribute the assets of the former Japanese National Railways (JNR) after its privatization in the mid-1980s. On October 22, 1998, the JNRSC was disbanded and placed under the Japan Railway Construction Public Corporation, JRCC, and its assets were transferred. Currently, the Japan Railway Construction, Transport and Technology Agency holds the liabilities and assets of the JNRSC.

The goal of disbanding the JNR was to privatize the newly created JR satellite companies, known collectively as the JR Group. Each of the seven companies was created as a kabushiki gaisha with the Japanese government as sole shareholder. Currently, JR East, JR West, JR Central and JR Kyushu are entirely privatized. JNRSC still holds titles to the remaining three JR Group companies, Hokkaido Railway Company (JR Hokkaido), Shikoku Railway Company (JR Shikoku), and the Japan Freight Railway Company (JR Freight).