The is a local rail line in Gunma, Japan, and is part of the
East Japan Railway Company
The is a major passenger railway company in Japan and the largest of the seven Japan Railways Group companies. The company name is officially abbreviated as JR-EAST or JR East in English, and as in Japanese. The company's headquarters are in ...
(JR East) network. Approximately following the
Agatsuma River, it is 55.6 km between and stations.
Operations
Although the official start of the line is at Shibukawa, all trains run through on the
Jōetsu Line
The is a major railway line in Japan, owned by the East Japan Railway Company (JR East). It connects Takasaki Station in Gunma Prefecture with Miyauchi Station (Niigata), Miyauchi Station in Niigata Prefecture, linking the northwestern Kanto regi ...
to/from either or .
Local trains run approximately once every hour, terminating at either or .
Limited Express
Kusatsu/Shima trains operate between in
Tokyo
Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...
and on the Agatsuma Line, stopping only at and . Depending on the day of the week, between 2 and 4 round trips operate each day, operating towards Naganohara-Kusatsuguchi in the morning, and towards Ueno in the afternoon.
Stations

All stations are in the Gunma Prefecture. Local trains stop at all stations.
Legend:
* ● : Limited Express Kusatsu/Shima stops
* |: Limited Express Kusatsu/Shima does not stop
* ∥ : Limited Express Kusatsu/Shima does not travel within this section
Rolling stock
Present
*
211-3000 series 4-car EMUs (since August 2016)
*
E257-5000 series
*
E257-5500 series
Former
*
115-1000 series 4-car EMUs (until March 2018)
*
185 series
The 185 series () is an electric multiple unit (EMU) train type operated by the East Japan Railway Company (JR East) primarily on mid-distance limited express services centering on Tokyo. As of August of 2024, two sets operate as Special Limit ...
7-car EMUs (''Kusatsu'' limited express services until March 2014)
*
651-1000 series
Four-car
211 series
The is a suburban electric multiple unit (EMU) train type introduced in 1985 by the Japanese National Railways (JNR). The trains are still being used by the East Japan Railway Company (JR East). They were formerly used by the West Japan Railwa ...
EMUs entered service on the line from 22 August 2016.
File:JNR 211-3000 02.JPG, A 211-3000 series EMU
History
The line opened on 2 January 1945 as the freight-only operating between and (present-day
Naganohara-Kusatsuguchi Station
is a passenger railway station in the town of Naganohara, Gunma, Naganohara, Gunma Prefecture, Japan, operated by East Japan Railway Company (JR East).
Lines
Naganohara-Kusatsuguchi Station is a station on the Agatsuma Line, and is located 42.0 ...
).
Passenger services were introduced as far as from 5 August 1945, to from 20 November 1945, and to Naganohara-Kusatsuguchi from 20 April 1946.

On 1 October 1952, the line was extended to , initially for freight only, but passengers services were also introduced from 21 June 1954.
Freight services between Shibukawa and Ōshi ceased as of 1 October 1966.
Services on the section between Naganohara and Ōshi were suspended as of 1 November 1970, and on 7 March 1971, a new line was opened beyond Naganohara to , with the entire line renamed Agatsuma Line at the same time.
The Naganohara-Kusatsuguchi to Ōshi line was formally closed as of 1 May 1971.
CTC signalling on the entire line was also commissioned at the same time.
With the privatization of
JNR on 1 April 1987, the Agatsuma Line came under the ownership of
JR East
The is a major passenger railway company in Japan and the largest of the seven Japan Railways Group companies. The company name is officially abbreviated as JR-EAST or JR East in English, and as in Japanese. The company's headquarters are in ...
.
It had been proposed to extend the line to Nagano, but geological exploratory drilling revealed extensive faulting beyond Ōmae, and as any extension would have required extensive tunnelling, this was considered impractical.
Yamba Dam construction
The construction of the
Yamba Dam required the realignment of the Agatsuma line between and . Work on the diversion was well advanced when a change of government in 2009 resulted in the project being halted. Another change of government in 2012 revived the project. Services on the old section of the line were suspended following the last scheduled service on 24 September 2014 to allow commissioning of the new alignment.
The new alignment opened for passenger services on 1 October 2014.
The new route is shorter, resulting in the shortest tunnel in Japan, the
Tarusawa Tunnel, being abandoned, although it is not inundated by the new dam.
"Farewell to Japan’s shortest rail tunnel"
Nippon TV
JOAX-DTV (channel 4), branded as (NTV) or Nippon TV, is a Japanese television station serving the Kantō region as the flagship station of the Nippon News Network and the Nippon Television Network System, owned and operated by the , a sub ...
, September 25, 2014 (video).
Points of interest
The Agatsuma Line is noted for numerous ''onsen
In Japan, are hot springs and the bathing facilities and Ryokan (inn), traditional inns around them. There are approximately 25,000 hot spring sources throughout Japan, and approximately 3,000 ''onsen'' establishments use naturally hot water ...
'' hot springs along the route. The famous hot springs at Kusatsu are some distance north of the line, but several rural ''onsen'' such as those at Shima, Sawatari, Kawarayu, and Shiriyaki are more accessible.
Mount Asama
is an active complex volcano in central Honshū, the main island of Japan. The volcano is the most active on Honshū. The Japan Meteorological Agency classifies Mount Asama as rank A. It stands above sea level on the border of Gunma prefecture ...
, Mount Kusatsu-Shirane
is a active volcano, stratovolcano in Kusatsu, Gunma, Japan. It is called Kusatsu Shirane to differentiate it from the Mount Nikkō-Shirane on the other side of Gunma Prefecture. The summit of Kusatsu-Shirane volcano, located immediately north ...
, and the Agatsuma Canyon can all be seen from the Agatsuma Line, though the canyon will be inundated when the Yamba Dam is commissioned.
References
{{East Japan Railway Company Lines
Lines of East Japan Railway Company
Rail transport in Gunma Prefecture
Railway lines opened in 1945
1067 mm gauge railways in Japan