Is a baked sweet potato, yakiimo. Yes!! Japanese sweet potatoes are so good!! They differ a bit from what I was used to in Belgium (they where orange inside, Japanese ones are yellow or the okinawan purple ones are (a very pretty) purple!). You can find them in supermarkets sometimes already baked and hot and ready to be eaten~ motly in autumn and winter but hey… I love them so much I did eat them in the summer haha
I think you break them in two and just eat them like that.
So sweeet and yummy!