Ekai Kawaguchi (February 26, 1866 – February 24, 1945) was first recorded Japanese citizen to travel to Tibet from Japan.
From an early age Kawaguchi, whose birth name was Sadajiro, was passionate about becoming a monk. In fact, his passion was unusual in a country that was quickly modernizing; he gave serious attention to the monastic vows of vegetarianism, chastity, and temperance even as other monks were happily abandoning them. As a result, he became disgusted with the worldliness and political corruption of the Japanese Buddhist world.
Kawaguchi devoted his entire time in Tibet to Buddhist pilgrimage and study. Although he mastered the difficult terminology of the classical Tibetan language and was able to pass for a Tibetan, he was surprisingly intolerant of Tibetans' minor violations of monastic laws, and of the eating of meat in a country with very little arable farmland. As a result, he did not fit in well in monastic circles, instead finding work as a doctor of Chinese and Western medicine. His services were soon in high demand.
https://en.wikipedia.org/wiki/Ekai_KawaguchiHis travelogue, quickly published based on talks he gave, shows his shock at the lack of hygiene amongst Tibetans, the filth of Tibetan cities, and by many Tibetan customs, including sexual practices, monastic immoderation, corruption and superstitious beliefs. On the other hand, he had great admiration for many Tibetans ranging from great religious and political leaders to common people and made many friends while he was in Tibet.