Japanese food by mailorder!
You can now get a lot of Japanese food by mail. To save on postage though try looking locally first, and ordering only hard to find items. Here are some items and brands that I use myself, starting with a few pantry essentials.
House - Shichimi Togarashi 0.63 Oz.Hidaka - Premium Authentic Hokkaido Japanese Kombu Dried Kelp Seaweed (Hai Dai) Value Twin Pack - 2x 2.1 OzHijiki Dried Seaweed
House - Shichimi Togarashi 0.63 Oz.
$3.29
A multi-layered spicy powder. Sprinkle on anything to add a bit of zing. Most often used to sprinkle on udon or soba noodles.
Hidaka - Premium Authentic Hokkaido Japanes...
$15.99
Konbu seaweed is an essential ingredient for making dashi stock.
Hijiki Dried Seaweed
$4.99
Dried seaweed that's good for you! See the justhungry.com site for recipes...
Goshoku All Natural Cut Fueru Wakame Seaweed Value 3 Packs - (3x 3.5 Oz)Dried shrimp - 3 ozStash Premium Toasted Nori Seaweed for Sushi, 10-Sheets  (Pack of 6)
Goshoku All Natural Cut Fueru Wakame Seawee...
$18.99
More healthy seaweed! Use wakame for salads and in miso soup.
Dried shrimp - 3 oz
$6.79
Little dried shrimp add great flavor to stir-fries and much more.
Stash Premium Toasted Nori Seaweed for Sush...

You need nori for sushi of course, and many other things. Get unflavored nori like this - flavored or "ajinori" (ajitsukenori)...
Ajinomoto - Hon Dashi (Soup Stock) 5.28 Oz.Kaneku Premium Wasabi Ko - Japanese Horseradish Powder Value Pack - 1.76 OzAo-Nori Seaweed
Ajinomoto - Hon Dashi (Soup Stock) 5.28 Oz.
$6.49
When you're in a hurry, it's convenient to use dashi stock granules.
Kaneku Premium Wasabi Ko - Japanese Horsera...
$5.99
Not the same as fresh grated wasabi of course, but really handy to have around. Have you tried wasabi mashed potatoes?
Ao-Nori Seaweed

Ao-nori is a green-colored powdered nori, sprinkled on many dishes like okonomiyaki.