The differences between Koreans, Chinese and Japanese are slight. The only way to really tell the difference to to live among them
Languages of Japan
The oral languages spoken by the native peoples of the insular country of Japan at present and during recorded history belong to either of two primary phyla of human language:
In addition to these two indigenous language families, there is Japanese Sign Language as well as significant minorities of ethnic Koreans and Chinese, who respectively constitute approximately 0.5% and 0.4% of the country's population and many of whom continue to speak their respective ethnic language in private contexts (see Zainichi Korean). There is also a notable history of use of Kanbun (Classical Chinese) as a language of literature and diplomacy in Japan, similar to the status of the Latin language in medieval Europe, which has left an indelible mark on the vocabulary of the Japanese language. Kanbun is a mandatory subject in the curricula of most Japanese secondary schools.
Japanese (日本語 Nihongo, [nihõŋɡo], [nihõŋŋo] ( listen)) is an East Asian language spoken by about 125 million speakers, primarily in Japan, where it is the national language. It is a member of the Japonic (or Japanese-Ryukyuan) language family, whose relation to other language groups, particularly to Korean and the suggested Altaic language family, is debated.
Little is known of the language's prehistory, or when it first appeared in Japan. Chinese documents from the 3rd century recorded a few Japanese words, but substantial texts did not appear until the 8th century. During the Heian period (794–1185), Chinese had a considerable influence on the vocabulary and phonology of Old Japanese. Late Middle Japanese (1185–1600) saw changes in features that brought it closer to the modern language, as well the first appearance of European loanwords. The standard dialect moved from the Kansai region to the Edo (modern Tokyo) region in the Early Modern Japanese period (early 17th century–mid-19th century). Following the end in 1853 of Japan's self-imposed isolation, the flow of loanwords from European languages increased significantly. English loanwords in particular have become frequent, and Japanese words from English roots have proliferated.
In a modern context, Japan–Korea relations pertain to three states: Japan, North Korea, and South Korea. Historically, Japan and Korea have had cultural interactions for more than 1,500 years ago and had direct political contact for almost as long. Korea became Japan's territory as a result of the Japan-Korea Annexation Treaty which was signed in 1910. When Japan was defeated in World War II, U.S. Army Forces proclaimed the occupation and administration of Korea. South Korea has been independent as of August 15, 1948, and North Korea became independent on September 9.
Diplomatic relations between Japan and South Korea were established in 1965. In the early 2000s, the Japanese–South Korean relationship soured when the Japanese Prime Minister Junichiro Koizumi visited the Yasukuni Shrine. Furthermore, conflicts continue to exist over claims of the Liancourt Rocks - a group of small islets halfway between the two countries.
Sakhalin Koreans are Russian citizens and residents of Korean descent living on Sakhalin Island, who trace their roots to the immigrants from the Gyeongsang and Jeolla provinces of Korea during the late 1930s and early 1940s, the latter half of the Japanese colonial era. At the time, the southern half of Sakhalin Island, then known as Karafuto Prefecture, was under the control of the Empire of Japan; the Japanese government both recruited and forced Korean labourers into service and shipped them to Karafuto to fill labour shortages resulting from World War II. The Red Army invaded Karafuto days before Japan's surrender; while all but a few Japanese there repatriated successfully, almost one-third of the Koreans could not secure permission to depart either to Japan or their home towns in South Korea. For the next forty years, they lived in exile. In 1985, the Japanese government offered transit rights and funding for the repatriation of the original group of Sakhalin Koreans; however, only 1,500 of them returned to South Korea in the next two decades. The vast majority of Koreans of all generations chose instead to stay on Sakhalin.
Due to differing language and immigration history, Sakhalin Koreans may or may not identify themselves as Koryo-saram. The term "Koryo-saram" may be used to encompass to all Koreans in the former USSR, but typically refers to ethnic Koreans from Hamgyŏng province whose ancestors emigrated to the Russian Far East in the 19th century, and then were later deported to Central Asia. The issue of self-identification is complicated by the fact that many Sakhalin Koreans feel that Koreans from Central Asia look down on them.
The Korean diaspora consists of roughly seven million people, both descendants of early emigrants from the Korean peninsula, as well as more recent emigres from Korea. Nearly four-fifths of expatriate Koreans live in just three countries: China, the United States, and Japan. Other countries with greater than 0.5% Korean minorities include Australia, Canada, Kazakhstan, New Zealand, and Uzbekistan. All these figures include both permanent migrants and sojourners. If one focuses on long-term residents, there were about 5.3 million Korean emigrants as of 2010.