Karafuto Fortress


The Karafuto Fortress was the defensive unit formed by the Karafuto fortification installations, and the Karafuto detachment of Japanese forces, the
88th Division. The headquarters was in Toyohara, capital of the province, based on the Suzuya plain, in the Southern Karafuto area, not far from the ports of Otomari and Maoka.

Conformation of Fortified district in Karafuto Prefecture

One example of such defensive structure was in Japanese fortifications to the north of Koton Fortress part of Shikuka Fortified District. It extended twelve kilometers along the front and was thirty kilometers deep, between the cities of Hanno, Futaro,
Horomi, Miyuki and Horonai with central command in Koton. In this area, along the principal railroad that crossed the island from north to south, there were 17 permanent emplacements, 31 artillery and 108 machine gun bunkers, 28 artillery and 18 mortar positions and 150 shelters, these installations was constructed by Obishiro Nayaro in 1939 over ancient fortifications from the Russian-Japanese War period. The Karafuto Mixed Brigade protecting the fortified district was expanded 28 February to 88th Division. Together with support units it numbered up to 20,000 officers and men. The Japanese had 10,000 Military veterans serving as reservists and civil volunteer defenders.
This structure was very similar in the following areas:
additionally including airbases, Naval bases, some Army or Navy detachments and others, along with civil defence units inland.

Karafuto Fortification system

Special frontier unit with HQ in Toyohara and detachments and
fortified installations in:

Southern Karafuto Fortress area

Toyohara Sub-Prefecture

Fortified District
Fortified District
Otomari Fortified District
Rutaka Fortified District
Fortified District
Maoka Fortified District
Tomarioru Fortified District

Shikuka Sub-Prefecture

Fortified District
Shikuka Fortified District
Fortified District
Kita Nayoshi Fortified District
Japanese naval forces, had some bases and infantry naval detachments in Maoka and Otomari ports, the principal ports in Karafuto. Probably there were some units in ports in coasts of Taraika Bay, and city of Esutoru at north of province.