Since ancient times in Japan, cleanliness has been seen as a moral virtue. It's part of living life well. And now the world is embracing a Japanese approach to keeping things neat and tidy. This time, our topic is tidying up, and how it reflects the spiritual heritage of Japan. Our expert guest is Nagisa Tatsumi, an author who writes about housework and daily life. One of her books focuses on the "art of discarding", and it has sold well over a million copies. And in Plus One, how to clean house, Japanese style.