Bank's in Japan are likely to be different from your home country. Here are the main differences you should be aware of:
  • ATMs are only in banks/convenience stores/post offices
  • ATMs are not 24/7. They close in the evening, and open in the morning.
  • ATMs are closed over the New Years holiday
  • You will often pay a small fee (around 200yen) to withdraw money at an ATM, unless it's your banks ATM during regular service hours.
  • To open an account you may need: Foreign Registration Card (gaijin card), Personal Stamp (hanko), passport.
  • Opening hours of banks in Japan are (generally) 9-10am to 3.30-5pm, week days ONLY.
    Note: this is generally during your scheduled work hours.
    (It is usually possible to go to the bank during work hours with your school's permission, if it is close by. In some cases you may have to use paid leave to go to the bank during school hours.)

Types of banks in Okayama:
Chugoku ginkou (also called 'Chugin')
This is where most prefectural JETs will have their salary deposited. This bank is notoriously unaccommodating and has
poor English options, none on their ATMs. Horrendous customer service. You will need several hours to resolve any issue.

Japan Post Bank (also called Yuucho Ginko)
Has an English website and English ATM options. Ubiquitous throughout Japan. You can also withdraw money from
foreign banks at Japan post ATMs. Many people open a second account here to make traveling around Japan easier.

Tomato bank
A popular bank with many branches in the Chugoku area and beyond.

ATMs in Japan can be used with cards to withdraw, deposit and send money (furikomi). Many do not have any English language options, but some do, notably Japan Post ATMs.
Bank ATMs are usually inside the building. The ATM area is generally open longer than bank service hours, but will charge your account an 'non-business hours' fee of around 100-200 yen if you use it after 5pm. Most close around 7pm.
Banks also charge you a 'weekend' fee for use, which can range from 100-400 yen.
Operating hours and ATM fees may be displayed near the ATM or on the screen before you complete a transaction.
Convenience stores, like 7-11 and Lawsons, often have ATMs. Be aware that these ATMs also have operating hours, generally between 9am and 5pm, and charge a fee in addition to your bank's. It is possible to get stuck in a far city on a Sunday evening with an ATM that is turned on and working, but will not dispense money outside of certain hours.

Bank Book
When you open an account with a bank, you will get both an ATM card and a bank book. The bank book is a small book which holds your account activity. It is updated manually by inserting it into an ATM and either selecting the update option, or when making a transaction (withdrawl, deposit, furikomi...). When the book runs out of pages, you'll need to get a new one from the bank by showing them your completed one.

Furikomi 振り込み - Money Transfers via ATM
Chugoku ginkou - When you visit a Chugoku Ginkou, you may be able to get an English guide to performing money transfers.
If not, here is a scanned copy, along with general ATM use guide:
Chugin ATM guide

Japan Post ATMs have English menus and instructions for simple transfers, but there are some sending options which are available only through the Japanese menu. You can ask the tellers to assist you if you can't read the kanji.

Generally there is no fee for sending money to another account at the same bank, but when sending money between banks the fees range from about 380 yen to 520 yen. Japan Post Bank usually has the lowest fees.