Yuzu is a variety of citrus fruit that has long been prized for its superb aroma. A winter specialty, it is an essential ingredient in Japanese cuisine. The Chugei district, in the east of Kochi Prefecture, produces more yuzu than anywhere else in Japan. This area used to depend on timber - it was the most important source of lumber in western Japan. But the forestry industry declined after World War II, so people in Chugei turned to cultivating yuzu trees instead. On this edition of Journeys in Japan, David Wells visits the area to discover the magic of yuzu. He meets the local people who grow the fruit, and explores the villages where this special citrus is an essential part of people's daily lives.