I found the summer version of the sweet potato salesman! This is the tofu salesman. He blows this horn to let you know he's coming down your street.I haven't bough anything from him because tofu is very, very confusing to me.
If you go to a grocery store here in Tokyo, there are several kinds of tofu. And given that the labels are all in Japanese, I have no idea what I'm buying. I have a Japanese cookbook here, but I've limited my cooking to chicken and beef. I'm even afraid of buying the fish here because a lot of the fish comes with head and tail included. No thanks!