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

Koton

Koton was a German Shepherd K9 Police Officer of the Kansas City, Missouri police department. He was teamed with Officer Patterson for two years and was responsible for more than 24 felony arrests at the time of his death.-Biography:...

 (Naramitoshi) Fortress (now Pobedino) part of Shikuka Fortified District

Fortified District

A Fortified District refers to the Japanese Army and in certain cases the Japanese Navy defensive fortified organization in World War II. It was created in the districts of Manchukuo; Chosen in Korea; Karafuto; Southern Sakhalin and the Kurile Islands - a front of over 6,000 kilometers.The Japanese...

 (FD

FD

- Science & Technology :* Canon FD lens mount* Fermi–Dirac statistics* Ferredoxin, a molecule functioning in electron transfer* File descriptor, a component in the Unix operating system* Finite difference, a mathematical expression...

). It extended twelve kilometers along the front and was thirty kilometers deep, between the cities of Hanno

Hanno

Hanno may refer to:* Hanno, Saitama, Honshū, Japan* Hanno , a lunar crater* Hanno , the pet white elephant of Pope Leo XPeople named Hanno:*Several ancient Carthaginians, including:...

, Futaro,
Horomi, Miyuki and Horonai

Klokovo

Klokovo is an air base in Russia located on north fringe of Tula. It has been home to 374 OVTAP flying Il-76 and An-22 large cargo planes, of 12th Mginskaya Krasnoznamennaya military-transport aircraft division.Then, a scholastic regiment of Tambov military aircraft school was situated there...

 with central command in Koton

Koton

Koton was a German Shepherd K9 Police Officer of the Kansas City, Missouri police department. He was teamed with Officer Patterson for two years and was responsible for more than 24 felony arrests at the time of his death.-Biography:...

. 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 Japanese 88th Division defended the FD organization. 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:

• Toyohara Fortified District
• Toyo-Sakae Fortified District
• Otomari Fortified District
• Rutaka Fortified District
• Honto
  Nevelsk
  Nevelsk is a port town in Sakhalin Oblast, Russia. Population 18,639 .-Geography:The town is located on the southwest coast of Sakhalin, 123 km from Yuzhno-Sakhalinsk, on the Sea of Japan.-History:...
  
   Fortified District
• Maoka Fortified District
• Tomarioru Fortified District
• Motodomari
  Vostochny
  Vostochny Port is intermodal container port at the Eastern end of the Trans-Siberian Railway, the largest port in the Russian Far East. It is located in Vrangel , Primorsky Krai. A deep-water port on the Nakhodka Bay , it operates year round and is suitable for handling large tonnage ships...
  
   Fortified District
• Shikuka Fortified District
• Esutoru Fortified District
• Kita Nayoshi
  Lesogorsk
  Lesogorsk is the name of several inhabited localities in Russia.Urban localities*Lesogorsk, Irkutsk Oblast, a work settlement in Chunsky District of Irkutsk Oblast...
  
   Fortified District

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:

Toyohara Sub-Prefecture

Toyohara Fortified District

• 3 detachments
• 3 fortifications
• 1 airfield

Otomari Sub-Prefecture

Toyo-Sakae Fortified District

• 1 detachment
• 4 fortifications
• 1 airfield

Otomari Fortified District

• 2 detachments
• 5 fortifications
• 1 airfield
• 1 naval base

Rutaka Fortified District

• 2 fortifications
• 1 airfield

Maoka Sub-Prefecture

Honto Fortified District

• 2 fortifications
• 1 airfield

Maoka Fortified District

• 2 fortifications
• 1 airfield
• 1 Naval Base

Tomarioru Fortified District

• 1 detachment

Shikuka Sub-Prefecture

Mototomari Fortified District

• 5 fortifications

Shikuka Fortified District

• 3 airfields
• 7 fortifications
• 2 detachments
• 3 frontier posts

Esutoru Sub-Prefecture

Esutoru Fortified District

• 7 fortifications
• 1 detachment
• 1 airfield

Kita Nayoshi Fortified District

• 3 fortifications
• 1 frontier post

Karafuto Detachment

• 88th Division HQ. (Toyohara) (Lt. Gen. Junichiro Mineki)

• 25th Infantry Regiment
• 125th Infantry Regiment
• 306th Infantry Regiment

• 88th Mountain Gun Regiment
• 88th Army Signal Unit
• 88th Transport Regiment
• 88th Railway Guards Unit

• 351st Special Guards Battalion
• 352nd Special Guards Battalion
• 353rd Special Guards Battalion

• 301st Special Guards Company
• 303rd Special Guards Engineer Unit

• 50th Infantry Battalion (served how Koton Fortress detachment)

Japanese Navy Detachments in Karafuto

Japanese naval forces, had some bases and infantry naval detachments
in Maoka (front at the Strait of Tartary

Strait of Tartary

Strait of Tartary is a strait in the Pacific Ocean dividing the Russian island of Sakhalin from mainland Asia , connecting the Sea of Okhotsk on the north with...

) and Otomari (in Aniwa Gulf) ports, the principal ports in Karafuto. Probably had some units in ports in coasts of Taraika Bay, and city of Esutoru at north of province.