“Does anyone know what this unusual cup from Japan is for?”
Answer: "It’s a sugar dish. It is called a sugar scuttle (or scuttle) because it is in the shape of a miniature coal-scuttle, the lumps of sugar resemble lumps of coal, in shape if not color."
I have one of these! In spite of what I thought when I first saw it at a garage sale it's comfortable beyond belief. I can sit on it for a couple of hours and get up with no trouble at all.
don't blame you, he got tatts and has no idea what they are?