yeah it will definitely be cheaper, and you will see alot of stuff there that is not available in Australia. Be careful though, because you may have warranty issues.
In terms of reels, stick to Daiwa, because most the reels in Japan are available here, whereas shimano have alot of japan only spec reels.
Japanese fishing shops are fantastic, the range of stuff they have is amazing. If it were me, I would be trying to get a rod there, as jap spec rods are a work of art, though it might be a little annoying for your dad to cart a rof tube along.
Definitely check out some of their lures tho. look at a website like this: http://www.lure.jp/ and look at their range of HB's, write the ones you want on a piece of paper to give to your dad to give to the shop owner and he will get all the lures for you.
With the current EXCELLENT exchange rate, you can some great lures (camions, chubbies, towards, mebapens...) all for about AUD$10-13.
if you can organise a group buy gimme a PM
anyway, enough rambling, hope that helps
Monk