How can I purchase something from Japan and have it imported to the U.S.?

MAKE SURE YOU KNOW REGION SPECIFIC, last thing you want is to buy the game and be unable to play it because you have a stateside 3ds. Also, nintendo is allowing us to cross save with the wii u version for character stats and abilities, currently asking if they will be able to cross region save.

Use forwarding companies such as Tenso: http://www.tenso.com/en/

They're basically made exactly to do stuff like buy things from Amazon JP outside of Japan.

Just remember there is an extra cost doing it this way, but it's better than nothing.

Also don't forget that the English version of Smash is only like a month away. If you have other uses for a Japanese 3DS, that's great, but otherwise you're gonna end up paying $400 to play one game.

If you do find a company to do that, note that the 3DS is not region-free, so you will have to have a Japanese region 3DS in order to play the game.

Spoiler alert: Duck Hunt Dog is real!