Have you seen Jetstar's 2 for 1 special to Japan? A word of advice for Sydney-siders - even though their website only lists Osaka on the special from Sydney, select Sydney-Tokyo and they just add Sydney-Gold Coast to the selection, don't be put off if you want to go to Tokyo. Or do what we're doing, fly into Tokyo and out of Osaka (but you have to ring and do that over the phone).
Now, just have to work out where else beside Tokyo we'll spend our time.
(Mmm, Casual Frozen Food - just noticed what this vending machine says. Wish I'd tried it!)