Kanji in the context of "Rangaku"

The Sinosphere, also known as the Chinese cultural sphere, East Asian cultural sphere, or the Sinic world, encompasses multiple countries in East Asia and Southeast Asia that were historically heavily influenced by Chinese culture. The Sinosphere comprises Greater China, Japan, Korea, Vietnam and historically the Ryukyuans. Other definitions may include the regions of modern-day Mongolia and Singapore, due either to historical Chinese influence or a contemporary overseas Chinese population. The Sinosphere is different from the Sinophone world, which indicates regions where the Chinese language is spoken.

Imperial China was a major regional power in Eastern Asia and exerted influence on tributary states and neighboring states, including Japan, Korea, and Vietnam. These interactions brought ideological and cultural influences rooted in Confucianism, Buddhism, and Taoism. The four cultures were ruled by their respective emperors under similar imperial systems, furthermore, the adoption of the Confucian-based imperial examination system deeply influenced the bureaucracy and social structure of Korea and Vietnam. Chinese inventions influenced, and were in turn influenced by, innovations of the other cultures in governance, philosophy, science, and the arts. Literary Chinese became the written lingua franca for bureaucracy and communications, and Chinese characters became locally adapted as kanji in Japan, hanja in Korea, and chữ Hán in Vietnam.

Traditional Chinese characters are a standard set of Chinese character forms used to write Chinese languages. In Taiwan, the set of traditional characters is regulated by the Ministry of Education and standardized in the Standard Form of National Characters. These forms were predominant in written Chinese until the middle of the 20th century, when various countries that use Chinese characters began standardizing simplified sets of characters, often with characters that existed before as well-known variants of the predominant forms.

Simplified characters as codified by the People's Republic of China are predominantly used in mainland China, Malaysia, and Singapore. "Traditional" as such is a retronym applied to non-simplified character sets in the wake of widespread use of simplified characters. Traditional characters are commonly used in Taiwan, Hong Kong, and Macau, as well as in most overseas Chinese communities outside of Southeast Asia. As for non-Chinese languages written using Chinese characters, Japanese kanji include many simplified characters known as shinjitai standardized after World War II, sometimes distinct from their simplified Chinese counterparts. Korean hanja, still used to a certain extent in South Korea, remain virtually identical to traditional characters, with variations between the two forms largely stylistic.

Minamoto (源; Japanese pronunciation: [mʲi.na.mo.to]) was a noble surname bestowed by the Emperors of Japan upon members of the imperial family who were excluded from the line of succession and demoted into the ranks of the nobility since 814. Several noble lines were bestowed the surname, the most notable of which was the Seiwa Genji, whose descendants established the Kamakura and Ashikaga shogunates following the Heian era. The Minamoto was one of the four great clans that dominated Japanese politics during the Heian period in Japanese history—the other three were the Fujiwara, the Taira, and the Tachibana.

In the late Heian period, Minamoto rivalry with the Taira culminated in the Genpei War (1180–1185 AD). The Minamoto emerged victorious and established Japan's first shogunate in Kamakura under Minamoto no Yoritomo, who appointed himself as shōgun in 1192, ushering in the Kamakura period (1192–1333 AD) of Japanese history. The name "Genpei" comes from alternate readings of the kanji "Minamoto" (源 Gen) and "Taira" (平 Hei).

The Taira (平; Japanese pronunciation: [taꜜi.ɾa]) was one of the four most important clans that dominated Japanese politics during the Heian period of Japanese history – the others being the Minamoto, the Fujiwara, and the Tachibana. The clan is divided into four major groups, named after the emperors they descended from: Kanmu Heishi, Ninmyō Heishi, Montoku Heishi, and Kōkō Heishi, the most influential of which was the Kanmu Heishi line.

In the twilight of the Heian period, the Taira controlled the boy emperor Antoku (himself the grandson of the powerful Kugyō Taira no Kiyomori) and had effectively dominated the Imperial capital of Heian. However, they were opposed by their rivals the Minamoto clan (the Genji), which culminated in the Genpei War (1180–1185 AD). The five-year-long war concluded with a decisive Taira defeat in the naval Battle of Dan-no-Ura, which resulted in the deaths of Antoku and Taira leaders. Following the war, the victorious Minamoto established Japan's first shogunate in Kamakura. The name "Genpei" comes from alternate readings of the kanji "Minamoto" (源 Gen) and "Taira" (平 Hei).

The modern Japanese writing system uses a combination of logographic kanji, which are adopted Chinese characters, and syllabic kana. Kana itself consists of a pair of syllabaries: hiragana, used primarily for native or naturalized Japanese words and grammatical elements; and katakana, used primarily for foreign words and names, loanwords, onomatopoeia, scientific names, and sometimes for emphasis. Almost all written Japanese sentences contain a mixture of kanji and kana. Because of this mixture of scripts, in addition to a large inventory of kanji characters, the Japanese writing system is considered to be one of the most complicated currently in use.

Several thousand kanji characters are in regular use, which mostly originate from traditional Chinese characters. Others made in Japan are referred to as "Japanese kanji" (和製漢字, wasei kanji), also known as "[our] country's kanji" (国字, kokuji). Each character has an intrinsic meaning (or range of meanings), and most have more than one pronunciation, the choice of which depends on context. Japanese primary and secondary school students are required to learn 2,136 jōyō kanji as of 2010. The total number of kanji is well over 50,000, though this includes tens of thousands of characters only present in historical writings and never used in modern Japanese.