There are quite a few companies in Japan that offer forwarding services. They are all in the expensive side of things, and worth the $ only if what you want to buy only exists in Japan or if you can save enough money by buying from a dealer who only ships within Japan.
I made a spreadsheet when I tried to choose one. I make no claim on the accuracy of this information of the suitability of these companies for any purpose. Actually, I haven't even used their services, since I decided to buy directly from amazon.com.jp instead. I don't know if it was cheaper, but it probably was safer to skip the middle man. Do your own research, this information is probably out of date!
|Name||URL||Notes||Mode||Registration||Monthly Fee||Usage Fee||Shipping methods||Payment Method||Consolidation?|
|Tenso||http://www.tenso.com/en/||EMS only?!||Free||0||490 up to 1kg, 980 up to 3kg||EMS||Credit card, Paypal|
|Danke Danke||http://www.dankedanke.com/en/||Monthly fee?!||Personal mailbox||Free||1575||1260 up to 2000g||EMS, DHL, SEA||Paypal|
|Not available?!||One by one (coming soon?)||None||0||1260 up to 2000g||EMS, DHL, SEA||Paypal|
|SeaServe||http://agent.seaserve.jp/||Quote||None||None||19% comission over product+shipping||EMS, SAL, SEA||Paypal|
|JShoppers||http://www.jshoppers.com/forward/index.asp||How do they earn money?? No shipping to Chile||Free||None||0||EMS (5% off)||Credit card, Paypal|
|Japan to Door||https://www.japantodoor.com/||Forwarding||Free||500 up to 0.5kg, 700 up to 1kg, 1000 up to 2kg, 2000 up to 5kg. USD5 commercial invoice. USD8 Repackaging. USD8 Consolidation.||EMS, AIR, SAL, SAGAWA||Paypal|
|Mailbox1||http://www.mailbox1.jp/||Not recommended (http://blog.jpopdb.org/index.php/blog/recommended-japanese-3rd-party-forwardin)||20USD||8.5USD|
|Japonic Express||http://www.japonic-express.com/en/en_index.html||Cranky website||Forwarding||380 up to 500g, 460 up to 1kg||EMS, SAL||Paypal|
|PakMail||http://www.pakmail.co.jp/en/||Quote. English not very good.||Forwarding||None||None||1050||EMS, SEA, DHL, Fedex, UPS, TNT||Credit card, Paypal|
|Shopping||None||None||1050 + 5% price|