Doai Station is a JR Joetsu Line station located in Minakami Town, Tone District, Gunma Prefecture, and is known as the "number one mole station in Japan." As its name suggests, the outbound platform is located about 82 meters underground in the Shin-Shimizu Tunnel, and from the aboveground station building to the platform, one descends a long staircase of 486 steps (462 steps and 24 steps), a very rare structure even nationwide. In particular, the nostalgic station building and the dimly lit staircase are like an entrance to another world, attracting not only railway fans but also many tourists.

The greatest attraction of this station is its extraordinary experience, full of a sense of secluded land. As you descend the long staircase, the cool air envelops your skin, and the sound of the train arriving deep underground and the reverberation of the tunnel create a unique atmosphere. You will feel as if you are on an adventure, and you can spend a special time that you cannot experience at other stations. The retro station building is sometimes used as a location for movies and dramas, and its unique atmosphere is gaining popularity.

The station is basically unmanned. There were plans to build an elevator, but it seems that they will not be built in the future.

Doai Station is used as one of the trailheads for Mt. Tanigawa, and is bustling with climbers. In recent years, the station has also become popular with railroad enthusiasts and tourists due to its unique atmosphere.