^ 99.9% of the sellers on Yahoo! Auctions Japan won't sell to buyers outside of Japan, so From Japan can act as your agent in Japan, to bid for you, receive your purchases, and send them to you. There are other proxy services like this around, but From Japan seems to have the cheapest fees.
From Japan's instructions are pretty clear (and in English), but it's helpful to be able to navigate the listings on Yahoo! Auctions yourself, either in Japanese or using an automatic translator.
The shipping costs listed by the sellers on Yahoo! Auctions Japan are only valid for shipping from the seller to From Japan (or to any other address within Japan). These are generally quite cheap; I've never seen the kind of price-gouging on shipping on Y!AJ that I sometimes see on eBay. You will, however, need to pay an
additional shipping charge to From Japan for them to ship your stuff from their offices to you, as well as several different fees. But From Japan will consolidate all of your auction purchases for up to a month, so you'll save on international shipping by buying a lot of things at once and having them shipped together.
You can also use From Japan to buy stuff on other Japanese websites that don't ship overseas, not just Y!AJ, and not just auctions.
To give you some idea of the cost of using From Japan, here's what I paid for my last batch of Y!AJ stuff through From Japan:
Total bid price of 14 auction lots on Y!AJ: ¥10,151
From Japan's ¥200 per auction fee: ¥2,800
From Japan's system usage fee: ¥933
From Japan's bank transfer fee: ¥2,184
From Japan's excess charge: ¥500 (I think this was because of my oversize poster)
Domestic delivery charge (shipping of all the individual items from their sellers to From Japan): ¥2,500
EMS shipping from Japan to California (all items combined in one box, total weight 4240 grams): ¥7,125
TOTAL: ¥26,193
Shipping charges were a bit high on this shipment because four of my 14 lots were Hello! Channel mooks (which added significantly to the weight of the parcel) and one was a rolled poster, which doubled the size of the box they had to use. You can also choose cheaper shipping options instead of EMS, if you like.
But here's all the stuff I got for that ¥26,193:
Hello! Channel Vol. 3 mook
Hello! Channel Vol. 5 mook
Hello! Channel Vol. 8 mook
Hello! Channel Vol. 11 mook
Morning Musume。DVD Magazine 6
Morning Musume。DVD Magazine 8
Kaitō Reinya Vol. 1 first press box with figure
Kaitō Reinya Vol. 2 first press box with figure
Coconuts Musume DVD (new)
SPEED SPIRITS COMPLETE DVD
Morning Musume。"I WISH" CD single, signed by Gotō Maki
Takahashi Ai H!P 7th Anniversary T-shirt
Morning Cop poster
Heike Michiyo first press photo cards (5)
Rio (Ebisu Muscats) clear file