There are isolated records of contact between Islam and Japan before the opening of the country in 1853, possibly as early as the 1700s; some Muslims did arrive in earlier centuries, although these were isolated incidents.
The earliest Western records of Japan can be found in the works of the Muslim cartographer Ibn Khordadbeh, who clearly mentions Japan as the "lands of Waqwaq" twice: East of China are the lands of Waqwaq, which are so rich in gold that the inhabitants make the chains for their dogs and the collars for their monkeys of this metal. They manufacture tunics woven with gold. Excellent ebony wood is found there.” And: “Gold and ebony are exported from Waqwaq. Mahmud Kashgari's 11th century atlas indicates the land routes of the Silk Road and Japan in the map's easternmost extent.
Within Kublai's court, his most trusted governors and advisers appointed by meritocracy with the essence of multiculturalism were: Semu, Hui, Koreans and Chinese. Because the Wokou extended support to the crumbling Song dynasty, Kublai Khan initiated the Mongol invasions of Japan.
The court of the Goryeo supplied Korean troops and an ocean-going naval force for the Mongol campaigns. Despite the opposition of some of his Confucian-trained advisers, Kublai decided to invade Japan, Burma, Vietnam, and Java, following the suggestions of some of his Mongol officials. He also attempted to subjugate peripheral lands such as Sakhalin, where its indigenous people eventually submitted to the Mongols by 1308, after Kublai's death.
During the 14th century, Hongwu Emperor of the Ming dynasty made Ryukyu Kingdom a tributary vassal, and ethnic Chinese settlers consolidated the islands for their ruler in Nanjing.
During that period there was contact between the Hui, general Lan Yu of the Ming dynasty and the swordsmiths of Japan. According to Chinese sources, Lan Yu owned 10,000 Katana, Hongwu Emperor was displeased with the general's links with Kyoto and more than 15,000 people were implicated for alleged treason and executed.
Early European accounts of Muslims and their contacts with Japan were maintained by Portuguese sailors who mention a passenger aboard their ship, an Arab who had preached Islam to the people of Japan. He had sailed to the islands in Malacca in 1555.
The first modern Muslim contacts were with Indonesians who served aboard British and Dutch ships in the late 19th century.
In the late 1870s, the biography of Muhammad was translated into Japanese. This helped Islam spread and reach the Japanese people, but only as a part of the history of cultures.
Another important contact was made in 1890 when the Ottoman Empire dispatched a naval vessel to Japan for the purpose of saluting the visit of Japanese Prince Komatsu Akihito to Constantinople several years earlier. This frigate was called the Ertugrul, and was destroyed in a storm along the coast of Wakayama Prefecture on September 16, 1890.
The first Japanese to go on the Hajj was Kotaro Yamaoka. He converted to Islam in 1909 in Bombay, after coming into contact with Russian-born writer, Abdürreşid İbrahim, whereupon he took the name Omar Yamaoka. Both were traveling with the support of nationalistic Japanese groups like the Black Dragon Society (Kokuryūkai), Yamaoka in fact had been with the intelligence service in Manchuria since the Russo-Japanese war. His official reason for travelling was to seek the Sultan's approval for building a mosque in Tokyo. This approval was granted in 1910, and the mosque was completed in 1938. Another early Japanese convert was Bunpachiro Ariga, who about the same time went to India for trading purposes and converted to Islam under the influence of local Muslims there, and subsequently took the name Ahmed Ariga. Yamada Toajiro was from 1892 for almost twenty years the only resident Japanese trader in Constantinople. During this time he served unofficially as consul. He converted to Islam, and took the name Abdul Khalil, and made a pilgrimage to Mecca on his way home.
The real Muslim community life however did not start until the arrival of several hundred Turko-Tatar Muslim refugees from Central Asia and Russia in the wake of the October Revolution. These Muslims, who were given asylum in Japan, settled in several main cities and formed small communities. They are estimated at less than 600 in 1938 for Japan proper, a few thousand on the continent. Some Japanese converted to Islam through contact with these Muslims.
The Kobe Mosque was built in 1935 with the support of the Turko-Tatar community of traders there. The Tokyo Mosque, planned since 1908 was finally completed in 1938, with generous financial support from the zaibatsu. Its first imams were Abdürreşid İbrahim (1857–1944), who had returned in 1938, and Abdulhay Qorbangali (1889–1972).
The Ahmadiyya Muslim Community was established in 1935 in Japan.
In the late Meiji period, close relations were forged between Japanese military elites with an Asianist agenda and Muslims to find a common cause with those suffering under the yoke of Western hegemony. In 1906, widespread campaigns were aimed at Muslims nations with journals reporting that a Congress of religions was to be held in Japan where the Japanese would seriously consider adopting Islam as the national religion and that the Emperor was at the point of becoming a Muslim.
Nationalistic organizations like the Ajia Gikai were instrumental in petitioning the Japanese government on matters such as officially recognizing Islam, along with Shintoism, Christianity and Buddhism as a religion in Japan, and in providing funding and training to Muslim resistance movements in Southeast Asia, such as the Hizbullah, a resistance group funded by Japan in the Dutch Indies. The Greater Japan Muslim League (大日本回教協会, Dai Nihon Kaikyō Kyōkai) founded in 1930, was the first official Islamic organisation in Japan. It had the support of imperialistic circles during World War II, and caused an "Islamic Studies Boom". During this period, over 100 books and journals on Islam were published in Japan. While these organizations had their primary aim in intellectually equipping Japan's forces and intellectuals with better knowledge and understanding of the Islamic world, dismissing them as mere attempts to further Japan's aims for a "Greater Asia" does not reflect the nature of depth of these studies. Japanese and Muslim academia in their common aims of defeating Western colonialism had been forging ties since the early twentieth century, and with the destruction of the last remaining Muslim power, the Ottoman Empire, the advent of hostilities in World War II and the possibility of the same fate awaiting Japan, these academic and political exchanges and the alliances created reached a head. Therefore, they were extremely active in forging links with academia and Muslim leaders and revolutionaries, many of whom were invited to Japan.
Shūmei Ōkawa, by far the highest-placed and most prominent figure in both Japanese government and academia in the matter of Japanese-Islamic exchange and studies, managed to complete his translation of the Qur'an in prison, while being prosecuted as an alleged class-A war criminal by the victorious Allied forces for being an 'organ of propaganda'. Charges were dropped for his erratic behaviour officially; however historians have speculated that the weakness of the charges against him was more likely the true reason. While Okawa did display unusual behaviour during the trial such as rapping on the head of Hideki Tōjō, he also stated that the trial was a farce and unworthy of being called one. He was transferred to a hospital on official claims of mental instability and then prison, and freed not long thereafter, dying a Muslim in 1957 after a quiet life where he continued lecturing, on his return to his home village and his wife, who survived him. He claimed to have seen visions of Muhammad in his sleep.
In the 1970s, another "Islamic Boom" occurred, this time due to the "Arab Boom" after the 1973 oil crisis. After realizing the importance of the Middle East and its massive oil reserves for the Japanese economy, the Japanese mass media have since been giving big publicity to the Muslim World in general and the Arab World in particular.
The Turks have been the biggest Muslim community in Japan until recently.
The Japanese invasion of China and South East Asian regions during the Second World War brought the Japanese in contact with Muslims. Those who converted to Islam through them returned to Japan and established in 1953, the first Japanese Muslim organisation, the Japan Muslim Association under the leadership of Sadiq Imaizumi.
The second president of the association was the Umar Mita, who was typical of the old generation, learning Islam in the territories occupied by the Japanese Empire. He was working for the Manshu Railway Company, which virtually controlled the Japanese territory in the northeastern province of China at that time. Through his contacts with Chinese Muslims, he became a Muslim in Peking. When he returned to Japan after the war, he made the Hajj, the first Japanese in the post-war period to do so. He also made a Japanese translation of the Qur'an from a Muslim perspective for the first time. Aljazeera also made a documentary regarding Islam and Japan called "Road to Hajj – Japan".
Though many Islamic organisations were established since the 1900s, each of them had only very few active members.
The Muslim community in Japan has a history of over 100 years, although some sources disagree. Historian Caeser E. Farah documented that in 1909 Abdul-Rashid Ibrahim was the first Muslim who successfully converted the first ethnic Japanese, and in 1935 Kobe Mosque—Japan's first Islamic building—was constructed. On 12 May 1938, a Mosque was dedicated in Tokyo.
In 1941, one of the chief sponsers of the Tokyo Mosque asserted that the number of Muslims in Japan numbered 600, with just three or four being native Japanese. Some sources state that in 1982 the Muslims numbered 30,000 (half were natives). Some ethnic Japanese women during the economic boom of the 1980s converted when large numbers of immigrants from Asia came and mixed with the local population. Most estimates of the Muslim population have been around 100,000 total. Islam remains a minority religion in Japan, and there is no evidence as to whether its numbers are increasing. Conversion is more prominent among young ethnic Japanese married women, as claimed by the The Modern Religion as early as the 1990s. The true size of the Muslim population in Japan remains a matter of speculation. Some Muslim organizations and media reports have put the number of Muslims in Japan at up to 100,000. The most serious work on this question has been done by Japanese scholars such as Hiroshi Kojima of the National Institute of Population and Social Security Research and Keiko Sakurai of Waseda University. Their estimates suggest a Muslim population of around 70,000, of which perhaps 90% are resident foreigners and about 10% native Japanese.
According to japanfocus.org, as of 2009 there were 30 to 40 single-story mosques in Japan plus another 100 or more apartment rooms set aside for prayers in the absence of more suitable facilities. 90% of these mosques use the 2nd floor for religious activities and the first floor as a halal shop (Imported food; mainly from Indonesia and Malaysia), due to financial problems, as membership is too low to cover up the expenses. most of these Mosques have only a capacity of 30 to 50 people. Antonio Inoki