There are three main ways in which Islam was
introduced into Japan.
(1)Through the Japanese soldiers who came into contact with Islamic society
during the occupation of the North China before WW1. Some Japanese
soldiers converted to Islam during this time.
(2)Through the Turkestan refugees in Japan who escaped from the pressure and oppression of the Russian Communists in Manchuria and Turkestan after the Russian Revolution. Later, they took an important role in introducing Islam to Japan.
(3)Through books and studies on Islam
The arrival of Islam in Japan through the two essential events mentioned above?the contact of Japanese soldiers with Chinese Muslims and the refugees from Turkestan?aroused Japanese scholars and learned people’s deep interest in Islam. They published their essays and studies as the introductions or criticisms of Islam. Such movements were encouraged by the central government of the Japanese Empire, which strategically needed any information on Islam in both mental and physical aspects so as to extend its occupation area, especially when it set Southeast Asia under occupation.
Slowly but surely, the Muslims made a steady progress in Islamic call activities. In the 1930’s, they successfully built three mosques in Tokyo?the capital--, Kobe and Nagoya and this brought good consequences with the translation of the Koran into Japanese ( by a Japanese scholar in Oriental studies ). There was an Islam exhibition held in Tokyo and Osaka, and many scholars participated. This display and the contributions of the Tokyo mosque gave the participants a favorable first impression of Islam. In the magazine entitled “The Islamic Movement”, which was published in 1940, a scholar from Indonesia stated;
“ I went to Japan and attended worship in a big mosque, where I looked
around at the visitors, wondering whether there were any Japanese Muslims,
to find only one Japanese. That there was no Japanese Muslims there suggests
there are a small number of Muslims in this country.” In other words,
the scale of Islamic call in Japan was much smaller than the other Asian
countries. Even though the call problem in Japan is yet to be solved and
there are ignorance of Islam and Arab countries, Islam is penetrating little
by little. This spread increased dramatically after WW2; the Muslim population
increased through the contact of Japanese soldiers with the locals in such
Southeast Asian countries as Malaysia and Indonesia.