Dressed in a crisp white jacket, white shirt and black tie, bartender Gen Yamamoto looks as though he has just emerged from a casino in a James Bond film. Inside his eponymous bar, which opened in February, the atmosphere is one of cool tranquility. The earth-toned walls complement the heavy, dark-wood bar, fashioned from a 500-year-old Mizunara tree, and the only decoration is a small vase filled with yellow blossoms in a nook near the entrance. There's no background music, just the tinkle of ice cubes and the sound of Yamamoto's wooden muddler transforming a tomato into the base of a cocktail.

"This is a Kakegawa tomato from Shizuoka Prefecture," he says, gently extracting the juice from the fruit before stirring in a dollop of tomato confiture and a shot of Kawabe komejōchū (shōchū made from rice). He points out that tomatoes originally come from Latin America, "so the farmer is trying to create a similar environment to give his tomatoes dense flavor."

A native of Mie Prefecture, Yamamoto switches effortlessly between Japanese and English, which he mastered during his eight-year stint as a mixologist in New York City. Before returning to Japan last year, he managed the bar at Brushstroke, a high-end Japanese restaurant opened by celebrity chef David Bouley, where he gained a reputation for creating surprising cocktails with fresh produce found at farmers markets.