This metal box is a double mystery! Where is it from? And what is it for? It is a silvertone metal tin (coated with something the can oxidize/corrode, obviously) with a latch at the front and no handle. It is very plain. The front has a Sonic head and date (1991) stamped into it, but no other mark. Inside, there can be found wrapped smaller tins. Clearly their sealed bags keep them from corroding. Each one is similarly embossed.
Notice that the one seems to be a different shape from the rest, with more rounded corners. But why would anyone need a metal box with more boxes inside? What are you supposed to do with it all? The suspected origin is Japan, but can you shed any light on this interesting item?