Kominato Railway

A 1920s Country Line, Registered Whole

The Kominato Railway (小湊鉄道, Kominato Tetsudō) is a 39.1-kilometer private line in Chiba Prefecture running from Goi Station in Ichihara City to Kazusa-Nakano Station in Otaki Town; its first section opened in 1925, and twenty-two of its station buildings, bridges and tunnels were registered as Registered Tangible Cultural Properties on May 2, 2017. The company was founded on May 19, 1917, and on its own signage and website it often uses the older character form 小湊鐵道.

The track reached the hills in three stages. According to the company's history, the 25.7-kilometer first section between Goi and Satomi opened on March 7, 1925, the 4.1-kilometer extension to Tsukizaki followed on September 1, 1926, and the final 9.3 kilometers to Kazusa-Nakano opened on May 16, 1928. The registered structures date from the same three campaigns: those between Goi and Satomi from around 1925, the Tsukizaki group from around 1926, and everything from the Okubo Tunnel onward from around 1928.

The line leaves the industrial shore of Tokyo Bay, follows the Yoro River inland through rice paddies and low hills, and ends among the wooded ravines of the Yoro Valley. A century on, its eighteen stations still rely on the same timber depots, steel girders and concrete bores that the company built in the Taishō and early Shōwa years.

What the Twenty-Two Listings Cover

The Agency for Cultural Affairs numbered the Kominato Railway listings 12-0193 through 12-0214 in line order, starting at Goi. Ten are station buildings: Kazusa Murakami, Ama-Ariki, Kazusa Yamada, Umatate, Kazusa Ushiku, Kazusa Tsurumai, Takataki, Satomi and Yorokeikoku, plus Tsukizaki, which is listed together with its platform. Four are working railway facilities: the engine shed and smithy at the Goi depot, the former Tsurumai power station, the freight shed at Kazusa Tsurumai, and Tsukizaki's old down-line platform. The remaining eight are five bridges and three tunnels.

Most of the stations follow what the agency calls the railway's standard design at opening: a single-storey timber building with a tiled roof that tucks an office and a waiting room under one ridge. The agency notes that the basic Kazusa Yamada block is smaller even than the most modest standard station of the contemporary state railways. In 1932 many stations were enlarged with rest rooms and extra waiting space.

The bridges are steel plate-girder and I-beam spans over the Yoro River and its tributaries: the First and Second Shibanoshita, and the First, Second and Fourth Yorogawa bridges. Girders on the Second and Fourth Yorogawa bridges still carry builder's plates from the Yokogawa Bridge Works. The three tunnels, Tsukizaki First, Okubo and Itaya, are concrete single-track bores 3.8 meters wide.

Two listings, Kazusa Tsurumai Station Building and Tsukizaki Station Building and Platform, were registered as models of good design; the other twenty were registered for their contribution to the historic landscape.

Down the Line, Goi to Kazusa-Nakano

The engine shed and smithy stand in the yard at Goi, the starting point. Heading southeast, the station buildings at Kazusa Murakami, Ama-Ariki and Kazusa Yamada follow at intervals of about three kilometers. South of Kazusa Yamada the track crosses the paddies on the First and Second Shibanoshita bridges, then clears the Yoro River on the First Yorogawa Bridge, the longest bridge on the line.

Past Umatate comes the Second Yorogawa Bridge and then Kazusa Ushiku. At Kazusa Tsurumai three listings survive side by side: the station building, the freight shed and the former power station. Beyond Takataki and Satomi lies the 1926 extension, where the Tsukizaki First Tunnel leads to Tsukizaki Station with its building and two platforms.

The 1928 section adds the Okubo Tunnel, the longest on the line, the Fourth Yorogawa Bridge on tall piers above a gorge, and Yorokeikoku Station. East of the station the Itaya Tunnel runs under the boundary between Ichihara and Otaki. The terminus at Kazusa-Nakano is not part of the registration.

Riding the Line: Tickets and Fares

Kominato's Goi Station shares a site with JR Goi Station on the Uchibo Line. According to the company, Suica, PASMO and other IC transit cards cannot be used on the Kominato line. Riders arriving from JR on an IC card tap out at the transfer gate at Goi to settle the JR fare, then buy a Kominato ticket in cash.

Most intermediate stations are unstaffed. Kazusa Murakami, Ama-Ariki, Kazusa Mitsumata, Kazusa Yamada and Umatate have ticket machines; elsewhere you board and buy a ticket from the conductor, who rides in the rear car.

A one-day pass covering the whole line costs 2,000 yen for adults and 1,000 yen for children, valid on the day of purchase. The company lists the ordinary fare from Goi to Kazusa Ushiku as 710 yen. In normal times the Boso Satoyama Torocco, an open-sided tourist train, takes about two hours from Goi to Yorokeikoku, stopping at Kazusa Ushiku, Takataki, Satomi, Tsukizaki and Yorokeikoku, and needs a reserved-seat ticket of 800 yen on top of the fare.

September 2026 Typhoon Damage and Suspension

Heavy rain from Typhoon No. 25 on September 21 and 22, 2026 damaged the line at 24 locations between Kazusa Ushiku and Kazusa-Nakano, with landslides onto the track and washed-out roadbed. In a statement issued on September 24, the company said trains between Goi and Kazusa Ushiku were running normally, that the Kazusa Ushiku to Kazusa-Nakano section was suspended all day until further notice, and that no replacement buses were planned because roads along the line were also closed.

That leaves ten of the twenty-two listings, from the Goi depot to Kazusa Ushiku Station, reachable by train, while the twelve from Kazusa Tsurumai onward cannot be reached by rail for now. The company's service update of September 25 says the Satoyama Torocco is expected to run only between Goi and Kazusa Ushiku from October. Check the official website for the latest status before you travel.

The bridges and tunnels are part of a working railway, so they can only be seen from outside the track. The stations are in daily use as well; keep clear of trains and passengers when you visit.