Over the past half decade, major changes have taken place in the demographics of foreign residents in Japan. Weekly Playboy's Dec. 18 issue devoted a four-page article to "Research into Vietnamese." Why Vietnamese? And why now?

"Their numbers in Japan have drastically increased," the magazine rationalizes. Up fourfold from five years ago, they grew by a remarkable 36.1 percent between 2015 and 2016. The Vietnamese population of 232,562 (as of end June 2017) has shot past Brazil to make them the fourth-largest nationality, and they may soon overtake the Philippines (251,934) for third place.

Take, for example, the city of Matsudo, a bed town of about 484,000 in Chiba Prefecture served by the JR Joban commuter line, about 21 minutes from Tokyo's Ueno Station. It currently boasts 15,058 foreign residents, including a growing community of Vietnamese.