Doai Station (土合駅, Doai-eki) is a passenger railway station in the town of Minakami, Gunma, Japan, operated by the East Japan Railway Company (JR East). It is jokingly known as "Japan's Number One Mole Station" (日本一のモグラ駅, Nippon ichi no mogura eki) due to the fact that passengers must make a 10 minute descent down a tunnel in order to reach the northbound platform. It is the deepest train station in Japan.

Doai Station is served by the Joetsu Line, and lies 69.3 km (43.1 mi) from the starting point of the line at Takasaki.

Doai Station is unusual in that it has two single side platforms, one of which is elevated, and the other is located underground within the Shin-Shimizu Tunnel. The station is unattended. The underground platform for the northbound trains (to Echigo-Yuzawa and Nagaoka) is located 70 metres (230 ft) underground, in the middle of the 13,490-metre (44,260 ft) long Shin-Shimizu Tunnel. It is only reachable by stairs, as there are no elevators or escalators. It takes ten minutes to walk the 486 steps from the ticket gate to the platform. The above-ground platform for the southbound trains (to Minakami) is at ground level.

1 (underground)	■ Joetsu Line	for Echigo-Yuzawa, Urasa, Nagaoka, and Niigata
2 (aboveground)	■ Joetsu Line	for Minakami, Takasaki, and Ueno

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  Station platform seen from the ground-level platform, July 2021
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  Ground platform, July 2021
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  Underground platform, July 2021
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  Platform waiting room, July 2021
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  Windbreaking structure in the connecting passageway, July 2021
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  Stairs from the underground platform, July 2021
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  The underground platform
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  The bottom of the steps at the underground platform
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  The ground-level platform

The station opened on 19 December 1936. With the privatization of Japanese National Railways (JNR) on 1 April 1987, the station came under the control of JR East.

The climb up the steps from the underground platform features at the start of the novel Seventeen (in Japanese, Climber's High) by Hideo Yokoyama, as well as in the NHK dramatization and the movie version Climber's High. It also makes an appearance in the manga and anime series Encouragement of Climb as a destination prior to climbing Mount Tanigawa, west of the site.

Online sources state it is haunted, and as such has become a local ghost hunting spot.

• Mount Tanigawa (one of the "100 famous mountains in Japan")
• National Route 291

• List of railway stations in Japan

Media related to Doai Station at Wikimedia Commons

• Station information (JR East) (in Japanese)