The stolen goods law in Japan is pretty interesting when
it gets _returning_stolen_goods_

Once the good(s) has pasted to a third person there is
really nothing that can be done when it comes to getting
the good(s) returned.

e.g.

Mr.A steals cels from studio Z
Mr.A then sells the goods to Cel Dealer B
Cel Dealer B sells the cels to Cels Collector C

By Japanese law Studio Z can not get their goods
back.

Cels Dealer B is also pretty much protected too. Because
generally there is no way to check whether the cels are
stolen and because Toei has released many of their cels
at events it makes it next to impossible.

I am not saying this is right or wrong, I am just saying it
is the current way Japanese law handles this matter and
it will be interesting to see the out come for this case.