Foreign tourists are making their way to Minakami, a town in Gunma Prefecture where a New Zealander, charmed by the nature there, promotes canyoning expeditions in English.

"Tone River's torrents are world-class," said Mike Harris, an outdoor adventure guide from New Zealand who provides the excursions. "People can experience great adventures here."

Originated in France, canyoning is an outdoor activity in which participants, wearing only a helmet and life jacket, are carried down a fast-flowing river. Popular in Switzerland and Nepal, participants can enjoy canyoning in places where the water level is low, unlike rafting.