It's pretty much the done thing that if you're going to be living in Japan for some time to open a Postal Savings account. The reason is that it's one of the few banks that has a nation wide network of branches and ATMs. One of the surprising things for me is that most banks in Japan are pretty much localised to a particular prefecture, go outside that prefecture and it's hard to find a branch except maybe in big cities like Tokyo or Osaka where most banks have a branch.
Bank accounts in Japan are a good example of how Japanese mix old and new. Firstly before opening the account I had to get a seal (called “inkan”) made up. You will also notice that the bank account actually has a bank book (I think those disappeared in the early 80s in Australia). However, it's a hightech bank book that you can use in ATMs to deposit and withdraw money. Also a few a week later I received my account connected smart card in the post which I can use to shop convenience stores, certain vending machines, and some other places. Also the ATM themselves are more complicated in Japan than Australia, to be able to handle bank books, plastic cards, and even count the money when you make a deposit (unlike the Australia ones which place the money in an envelope and hope it gets counted correctly manually later, and doesn't actually get credited to your account for a week!).
Another good point is you can keep only a few yen in your account and not have it disappear with bank fees. There are no bank fees! Can you imagine that! At last a county, where people have a hope of getting ahead even if they can only manage to deposit a little bit in their bank account each month. Try that in Australia and it will disappear with bank fees before the next month comes around, unless you have at least $500-2000 (depending on type of account). Then there's unlimited transactions without fees, plus they don't charge any counting fees if you go to the bank with the contents of your money box. The negative side about Japanese banks is that they don't pay any interest, unless you make a term deposit.
The other thing was is because of the competition for customers between banks, I got some small presents from the bank to say thank you for choosing them!