Japan has successfully moved from a bucket-list destination to a much more realistic getaway for Indian travelers. What would it take for India to crack Japan’s top five source markets?

This country has the the largest nominal GDP in Asia and the second-largest globally, behind the USA with $30.33 trillion (£24 trillion).

Work is well under way on the 316-mile high-speed line connecting Mumbai with Ahmedabad in Gujarat province. The huge project ...