For the most devout followers of Islam, traveling to Japan has often spelled trouble.

Some may recall entering clothing shops in a desperate search for fitting rooms where they could perform one of their five daily prayers. Others may cringe at the times they had to prostrate themselves in the corner of an airport lounge, only to invite suspicious glances from other travelers. And finding a halal-certified restaurant has always been a laborious task.

But the days are gone when such inconveniences had to be considered one of the inescapable quirks of visiting Japan.