Yokai: the collective name for all sorts of bizarre creatures and supernatural phenomena in Japanese folklore. They have a very long history in Japan, and these days they often feature in video games, anime, manga and many other contexts. Yokai culture, with its huge variety of uncanny creatures, offers a window on the Japanese mind. Our expert guest this time is Kazuhiko Komatsu, perhaps the world's leading authority on yokai. And in Plus One, visiting yokai relics.