ghostdncr - Heres where there from, a bit of a way off but 30minutes ride for me! if you really wanna know i'm sure they can tell you what they are for/from.
They do ship to the states but it'll be the postage that costs, there something like $12/13?
Its a damn site tronger than even the most expnsive touring cases i've seen, but also a fair bit heavyer, but it makes feck all difference to this bike so i can assure you it'll make even less difference to anything thats a reasonable size.
taki5 - tbh i agree to an extent.. when its loaded up with anything heavy then it wont go well, but it you use the higher up stuff for roll mats, sleeping bag, light clothes e.t.c. then theres no problem. Start carrying beer kegs in there and its a different story.
As said, mine is more for a place where my elmit wont get rained on and gloves wont be stolen. Haveing said that I do take my bag and books in there too with no problems.
Another factor is (i'm not sure how clear it is from the pic) but its over the back seat, japanese 125s are designed with tiny japanese folk in mind (my reccord is picking up three in one go) so its all on there, reasonably far forward.. if you can concieveably carry a person on there why on earth wouldn't you be able to carry 25% of the weight of one? weight evenly distributed carefully enough..
Shift that weight further back and i'd not be quite so confident about it.
Dont be affraid to experiment, but if it turns out shit be prepared to rearrange things