Overview: Sweet potatoes are widely grown and enjoyed in Japan. They're baked, fried, served in stews and used to make desserts. Throughout history, they have offered a solution to food shortages. And nowadays, they can even help to keep a building cool in summer. Our guest, researcher Hashimoto Ayuki, introduces us to new ways of enjoying this versatile vegetable. And in Plus One, we see some innovative takes on mobile baked potato sales.