Overview: Kotatsu are low tables with a heat source underneath, and a blanket draped over the top. For hundreds of years, Japanese have gathered around them in the cold winter months. They're cozy and comfortable; perfect for watching TV, studying and chatting to family and friends. Our guest, architect and university professor Watanabe Shinichi, talks about the social and environmental benefits of Kotatsu. And in Plus One, Kanoa tries out Kotatsu in some unusual locations.