So many Japanese online shopping sites don't allow you to ship an item outside of Japan, and even if they do, the overseas shipping prices can go sky high. Tenso.com acts as the middle-man - your goods get sent to them, and then they send it to you, for the real EMS postage costs. Therefore, as the goods get sent to the Japan-based Tenso.com warehouses first, this means that you can buy stuff from those sites that don't allow shipping outside of Japan.
Not only that, but the first 10,000 customers get another 50% off shipping costs.
My friend tried it recently and the goods got to her quickly and smoothly.
Quite a cool find I think.
If I had money, that is.
(And no, I'm not on commission. Doh!)