Japanese sweet potatoes, also called Japanese yams, or satsumaimo, are small to medium size potatoes with a pinkish purple exterior and a light yellow interior. These potatoes are extremely popular in Japan and are most often eaten as a snack or as a side dish, bare, without any added seasoning.
Japanese sweet potatoes taste much sweeter than orange sweet potatoes, which is why they are often used in desserts. The texture, once cooked, is more dense and chewy, like a pound cake.