Amid the lush greenery of Ayacho in Kyushu’s Miyazaki Prefecture, where a forest straddles a tropical-temperate zone inside the UNESCO-designated Aya Biosphere Reserve, a natural winemaker has quietly been rewriting the rules of wine production.

Katsuki Wines, opened in 2017 by Miyazaki City native Yoshitada Katsuki, was never expected to succeed. In a region of Japan that sees nearly 3,000 millimeters of annual rainfall — double or even triple the levels of Japan’s best-known wine-producing prefectures, such as Yamanashi and Hokkaido — Miyazaki’s moist climate and resulting abundance of critters seemed to make winemaking a futile craft.

Against all odds, however, Katsuki’s intensive efforts have paid off to create a thriving winery. Employing 100% natural production methods, he has created seven types of wine whose inventory regularly sells out via his online shop, despite a price tag of ¥7,000 to ¥10,000 per bottle — significantly higher than most domestic wines. His bottles also line the shelves of specialty shops nationwide, including Ginza Six in Tokyo.