Japanese language has been using Sanskrit phonology. Developed Kanji-kana writing system.
1868-1900, they invented many vocabularies and kanji to translate European thoughts into Japanese. It took about 30 years to convert European thoughts into Japanese. 1/2

Rash Behari Bose arrived Japan in 1915 at age 29. He picked up Japanese very quickly and was publishing in Japanese by 1929. Japanese then were publishing both new and old knowledges of the world all in Japanese and Rash Behari Bose was reading those. 2/2

At the same time, Japanese government was sending many Japanese of various capacities to India to fully investigate the true state of British colonization. Those reports are fully available in Japan, and many of them are online.