Gunma

Gunma is shaped like a crane in flight, a comparison every local schoolchild learns from the Jomo Karuta card game. Mountains cover about two thirds of it: the Mikuni range on the Niigata border, the volcanoes of Kusatsu-Shirane and Asama in the west, and the three 'Jomo mountains' – Akagi, Haruna and Myogi – that frame the plain around Maebashi and Takasaki. The Tone River, Japan's largest by catchment area, rises in the north near Minakami.

Volcanism has given the prefecture its many onsen. Kusatsu, with its strongly acidic water and the steaming yubatake in the town square, is among the most famous hot springs in Japan; Ikaho, Minakami, Shima, Manza and Hoshi are other classic spa towns. In the north-east, part of the high moor of Oze lies in Gunma.

From the late Edo period Gunma was the heart of Japanese sericulture and silk reeling. The Tomioka Silk Mill, founded by the Meiji government in 1872, was inscribed as World Heritage in 2014 together with related sites. Today the prefecture is an industrial centre – Subaru builds cars in Ota – and a major producer of vegetables and konnyaku for the Tokyo market.

The name comes from Gunma district (群馬郡), one of the ancient districts of Kozuke province around present-day Takasaki and Shibukawa; it was earlier written with characters read 'Kuruma'. Gunma Prefecture was first formed in 1871, merged with Iruma into Kumagaya Prefecture in 1873, and re-established in 1876 within the borders of Kozuke. The choice of capital was long disputed between Takasaki and Maebashi; Maebashi became the formal seat in 1881.

The south-east of Gunma is part of the Kanto Plain, where the Tone, Karasu and Watarase rivers flow through Takasaki, Maebashi, Isesaki and Ota. The rest is mountain country: the Mikuni Mountains with Tanigawa-dake along the main watershed of Honshu; the volcanic plateau of Kusatsu and Manza; Mount Asama on the Nagano border; the Oze highlands in the north-east; and the steep, deeply eroded peaks of Myogi and the Kanra hills in the south-west. Joshin'etsu Kogen, Oze and Nikko national parks extend into the prefecture.

Gunma's plain has hot summers with frequent thunderstorms – Tatebayashi and Isesaki regularly record some of Japan's highest temperatures – and dry winters swept by the karakkaze, a cold, dry north-westerly that has already dropped its snow on the Japan Sea side. The mountains on the Niigata border, around Minakami and Oze, receive heavy snow and support ski resorts.

Gunma has one of the densest concentrations of burial mounds (kofun) in eastern Japan, evidence of a powerful regional elite in the fifth and sixth centuries. The Kozuke Sanpi, three inscribed stone monuments of the seventh and eighth centuries at Takasaki, are listed in UNESCO's Memory of the World. In the fourteenth century Nitta Yoshisada, a warrior from eastern Kozuke, led the army that destroyed the Kamakura shogunate in 1333.

In the Sengoku period the province was contested by the Uesugi, Takeda and Hojo. Under the Tokugawa it was divided among domains including Takasaki, Maebashi, Numata and Annaka, crossed by the Nakasendo and the road to the Sado gold mines. The eruption of Mount Asama in 1783 buried the village of Kanbara under a debris flow and deepened the Tenmei famine.

From the 1850s, silk exports through Yokohama made Gunma rich. The government-built Tomioka Silk Mill (1872) introduced French reeling technology, and the prefecture's sericulture households, in which women earned much of the income, became proverbial. In the twentieth century Nakajima Aircraft grew up in Ota, the predecessor of today's Subaru; the Joetsu and Hokuriku Shinkansen made Takasaki a major rail junction.

Gunma's identity rests on silk, hot springs and a certain rough-hewn self-image summed up in the old saying 'kakaa-denka to karakkaze' – the wives rule the house, and the dry wind blows. Almost everyone raised in the prefecture knows the 44 verses of the Jomo Karuta card game, created in 1947 to teach local history and geography.

Gunma is a wheat and noodle country rather than a rice country: dry winters suited winter wheat, and flour dishes such as udon, okkirikomi and yakimanju form its everyday food. The prefecture grows the vast majority of Japan's konnyaku, as well as Shimonita leeks and summer cabbage from Tsumagoi.

Manufacturing dominates Gunma's economy. Ota is the home of Subaru's main car plants, and the belt from Takasaki to Isesaki and Ota hosts automotive suppliers, electronics, machinery and food processing. Agriculture specialises in high-value crops for the Tokyo market: summer cabbage from the Tsumagoi plateau, konnyaku, leeks, cucumbers and dairy. Onsen tourism and skiing support the mountain areas.