Sakhalin in the context of Qing dynasty

The Sea of Japan (see below for other names) is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific Ocean. This isolation also affects faunal diversity and salinity, both of which are lower than in the open ocean. The sea has no large islands, bays or capes. Its water balance is mostly determined by the inflow and outflow through the straits connecting it to the neighboring seas and the Pacific Ocean. Few rivers discharge into the sea and their total contribution to the water exchange is within 1%.

The seawater has an elevated concentration of dissolved oxygen that results in high biological productivity. Therefore, fishing is the dominant economic activity in the region. The intensity of shipments across the sea has been moderate owing to political issues, but it is steadily increasing as a result of the growth of East Asian economies.

The Sea of Okhotsk is a marginal sea of the northwestern Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands on the southeast, Japan's island of Hokkaido on the south, the island of Sakhalin along the west, and a stretch of eastern Siberian coast along the west and north. Its northeast corner is the Shelikhov Gulf. The sea is named for the port of Okhotsk, itself named for the Okhota River.

Hokkaido (Japanese: 北海道, Hepburn: Hokkaidō; pronounced [hok.kaꜜi.doː] , lit. 'Northern Sea Circuit'; Ainu: Aynu Mosir, lit. 'Land of the Ainu') is the second-largest and northernmost of Japan's four main islands. Together with its surrounding islands, it comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu. The two islands are connected by railway via the Seikan Tunnel.

The largest city on Hokkaido is its capital, Sapporo, which is also its only ordinance-designated city. Sakhalin lies about 43 kilometres (27 mi) to the north of Hokkaidō. To the east and northeast are the Kuril Islands, which are administered by Russia. The four most southerly are claimed by Japan. Hokkaido's position on the northern end of the Japanese archipelago results in a colder climate, with the island seeing significant snowfall each winter. Despite the harsher climate, it serves as an agricultural breadbasket for many crops.

The climate of Ireland is mild, humid and changeable with abundant rainfall and a lack of temperature extremes. Ireland's climate is defined as a temperate oceanic climate, or Cfb on the Köppen climate classification system, a classification it shares with most of northwest Europe. The island receives generally warm summers and cool winters.

As Ireland is downwind of a large ocean, it is considerably milder in winter than other locations at the same latitude, for example Newfoundland in Canada or Sakhalin in Russia. The Atlantic overturning circulation, which includes ocean currents such as the North Atlantic Current and Gulf Stream, releases additional heat over the Atlantic, which is then carried by the prevailing winds towards Ireland giving, for example, Dublin a milder winter climate than other temperate oceanic climates in similar locations.

Karafuto Prefecture (樺太庁, Karafuto-chō; Japanese pronunciation: [ka.ɾa.ɸɯ̥.to]) was established by the Empire of Japan in 1907 to govern the southern part of Sakhalin. This territory became part of the Empire of Japan in 1905 after the Russo-Japanese War, when the portion of Sakhalin south of 50°N was ceded by the Russian Empire under the Treaty of Portsmouth.

Karafuto Prefecture was established in 1907 to govern Karafuto, which was part of Japan's External Land (Gaichi), until it was incorporated into an Inner Land (Naichi) of the Japanese metropole in April 1943. Ōtomari (Korsakov) was the capital of Karafuto from 1905 to 1908 and Toyohara (Yuzhno-Sakhalinsk) from 1908 to 1945.

Hokkaido (Japanese: 北海道, Hepburn: Hokkaidō; pronounced [hok.kaꜜi.doː] , lit. 'Northern Sea Circuit'; Ainu: Aynu Mosir, lit. 'Land of the Ainu') is the second-largest and northernmost of Japan's four main islands. Together with its surrounding islands, it comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaido from Honshu. The two islands are connected by railway via the Seikan Tunnel.

The largest city on Hokkaido is its capital, Sapporo, which is also its only ordinance-designated city. Sakhalin lies about 43 kilometres (27 mi) to the north of Hokkaido. To the east and northeast are the Kuril Islands, which are administered by Russia. The four most southerly are claimed by Japan. Hokkaido's position on the northern end of the Japanese archipelago results in a colder climate, with the island seeing significant snowfall each winter. Despite the harsher climate, it serves as an agricultural breadbasket for many crops.

Ezo, Yezo or Yeso (蝦夷; Japanese pronunciation: [eꜜ.(d)zo]) is the Japanese term historically used to refer to the people and the lands to the northeast of the Japanese island of Honshu. This included the northern Japanese island of Hokkaido, which changed its name from "Ezo" to "Hokkaidō" in 1869, and sometimes included Sakhalin and the Kuril Islands. The word Ezo means 'the shrimp barbarians' in Japanese.

In reference to the people of that region, the same two kanji used to write the word Ezo can also be read Emishi. The descendants of these people are most likely related to the Ainu people of today.

The Okhotsk plate is a minor tectonic plate covering the Kamchatka Peninsula, Magadan Oblast, and Sakhalin Island of Russia; Hokkaido, Kantō and Tōhoku regions of Japan; the Sea of Okhotsk, as well as the disputed Kuril Islands.

Japan's principal fault system is the zone where the Amur plate, the Eastern edge of the Eurasian plate, meets the Okhotsk plate, sometimes considered the Western edge of the North American plate.

Khabarovsk Krai (Russian: Хабаровский край, romanized: Khabarovskiy kray, IPA: [xɐˈbarəfskʲɪj kraj]) is a federal subject (a krai) of Russia. It is located in the Russian Far East and is administratively part of the Far Eastern Federal District. The administrative centre of the krai is the city of Khabarovsk, which is home to roughly half of the krai's population and the largest city in the Russian Far East (just ahead of Vladivostok). Khabarovsk Krai is the third-largest federal subject by area, and had a population of 1,343,869 as of 2010.

Being dominated by the Siberian High winter cold, the continental climates of the krai see extreme freezing for an area adjacent to the sea near the mid-latitudes, but also warm summers in the interior. The southern region lies mostly in the basin of the lower Amur River, with the mouth of the river located at Nikolaevsk-on-Amur draining into the Strait of Tartary, which separates Khabarovsk Krai from the island of Sakhalin. The north occupies a vast mountainous area along the coastline of the Sea of Okhotsk, a marginal sea of the Pacific Ocean. Khabarovsk Krai is bordered by Magadan Oblast to the north; Amur Oblast, Jewish Autonomous Oblast, and the Sakha Republic to the west; Primorsky Krai to the south; and Sakhalin Oblast to the east.

Sakhalin Oblast (Russian: Сахали́нская о́бласть, romanized: Sakhalinskaya oblastʹ, IPA: [səxɐˈlʲinskəjə ˈobləsʲtʲ]) is a federal subject of Russia (an oblast) comprising the island of Sakhalin and the Kuril Islands in the Russian Far East. The oblast has an area of 87,100 square kilometers (33,600 sq mi). Its administrative center and largest city is Yuzhno-Sakhalinsk. As of the 2021 Census, the oblast has a population of 466,609.

The vast majority of the oblast's residents are ethnic Russians, with a small minority of Sakhalin Koreans. Sakhalin Oblast is rich in natural gas and oil, and is Russia's second wealthiest federal subject after the Tyumen Oblast. It borders by sea Khabarovsk Krai to the west and Kamchatka Krai to the north, along with Hokkaido, Japan to the south.

The Ainu in Russia are an Indigenous people of Siberia located in Sakhalin Oblast, Khabarovsk Krai and Kamchatka Krai. The Russian Ainu people (Aine; Russian: айны, romanized: Ayny), also called Kurile (курилы, kurily), Kamchatka's Kurile (камчатские курилы, kamchatskiye kurily / камчадальские айны, kamchadalskiye ayny) or Eine (эйны, eyny), can be subdivided into six groups.

Although only around 100 people currently identify themselves as Ainu in Russia (according to the census of 2010), it is believed that at least 1,000 people are of significant Ainu ancestry. The low numbers identifying as Ainu are a result of the refusal by the government of the Russian Federation to recognise the Ainu as a "living" ethnic group. Most of the people who identify themselves as Ainu live in Kamchatka Krai, although the largest number of people who are of Ainu ancestry (without acknowledging it) are found in Sakhalin Oblast. Many local people are ethnically Ainu or have significant Ainu ancestry but identify as Russian or Nivkh and speak Russian as mother tongue, often not knowing of their Ainu ancestry.

Oroks (Ороки in Russian; self-designation: Ulta, Ulcha), sometimes called Uilta, are a people in the Sakhalin Oblast (mainly the eastern part of the island) in Russia. The Orok language belongs to the Southern group of the Tungusic language family. According to the 2002 Russian census, there were 346 Oroks living in Northern Sakhalin by the Okhotsk Sea and Southern Sakhalin in the district by the city of Poronaysk. According to the 2010 census there were 295 Oroks in Russia.

The Nivkh, or Gilyak (also Nivkhs or Nivkhi, or Gilyaks; ethnonym: Нивхгу, Nʼivxgu (Amur) or Ниғвңгун, Nʼiɣvŋgun (E. Sakhalin) "the people"), are an indigenous ethnic group inhabiting the northern half of Sakhalin Island and the lower Amur River and coast on the adjacent Russian mainland. Historically, they may have inhabited parts of Manchuria.

Nivkh were traditionally fishermen, hunters, and dog breeders. They were semi-nomadic, living near the coasts in the summer and wintering inland along streams and rivers to catch salmon. The land the Nivkh inhabit is characterized as taiga forest with cold snow-laden winters and mild summers with sparse tree cover. The Nivkh are believed to be the original inhabitants of the region, and to derive from a proposed Neolithic people that migrated from the Transbaikal region during the Late Pleistocene.

Korean is the native language for about 81 million people, mostly of Korean descent. It is the national language of both North Korea and South Korea. In the south, the language is known as Hangugeo (South Korean: 한국어) and in the north, it is known as Chosŏnŏ (North Korean: 조선어). Since the turn of the 21st century, Korean popular culture have spread around the world through globalization and cultural exports.

Beyond Korea, the language is recognized as a minority language in parts of China, namely Jilin, and specifically Yanbian Prefecture, and Changbai County. It is also spoken by Sakhalin Koreans in parts of Sakhalin, the Russian island just north of Japan, and by the Koryo-saram in parts of Central Asia. The language has a few extinct relatives which—along with the Jeju language (Jejuan) of Jeju Island and Korean itself—form the compact Koreanic language family. Even so, Jejuan and Korean are not mutually intelligible. The linguistic homeland of Korean is suggested to be somewhere in contemporary Manchuria. The hierarchy of the society from which the language originates deeply influences the language, leading to a system of speech levels and honorifics indicative of the formality of any given situation.

The Sakhalin Island Arc (Russian Сахалинские острова) is an ancient volcanic arc dating from the Early Miocene. The arc was a result of the Okhotsk Plate subducting beneath the Eurasian Plate in the convergence zone. The arc runs from mainland Asia through Sakhalin Island into central Hokkaido and the collision zone around the Daisetsuzan Volcanic Group, where the Kuril Island Arc and the Northeastern Japan Arc meet.

The Soviet–Japanese War was a campaign of the Second World War that began with the Soviet invasion of Manchuria following the Soviet declaration of war against Japan on 8 August 1945. The Soviet Union and Mongolian People's Republic toppled the Japanese puppet states of Manchukuo in Manchuria and Mengjiang in Inner Mongolia, as well as northern Korea, Karafuto on the island of Sakhalin, and the Kuril Islands. The defeat of Japan's Kwantung Army helped bring about the Japanese surrender and the end of World War II. The Soviet entry into the war was a factor in the Japanese government's decision to surrender unconditionally, as it was made apparent that the Soviet Union was not willing to act as a third party in negotiating an end to hostilities on conditional terms.

"Mainland Japan" (内地, naichi; lit. '"inner lands"') is a term used to distinguish Japan's core land area from its outlying territories. "Mainland Japan" was an official term in the pre-war period, distinguishing Japan proper from its overseas territories (外地, gaichi, lit. "outer lands") in the Far East, such as Japanese Taiwan, Japanese Korea, Karafuto, the South Seas Mandate, and the Kwantung Leased Territory. After the end of World War II, its usage became less common and lost its previous legal significance.

The term's literal Japanese meaning might best be translated as "inner Japan" or "inner lands". The term "mainland" is somewhat inaccurate since it usually refers to all or part of a continental landmass, rather than islands. In the pre-1945 period, the "inner lands" included the Japanese archipelago, itself including the Ryukyu Islands and other island chains to the south of Honshu. The "inner lands" also referred during 1875–1945 to the Japanese-controlled Kuril Islands and during 1943–1945 to Karafuto, the southern half of the island of Sakhalin.