The Basic Bank Account in Japan - Types of Banks

 There are several national mega banks, numerous regional and local banks, as well as many online banks.  The lines between these are a bit blurred in some cases, but these are the three main categories for practical purposes.  

Mega banks will have the most branches around the country, and you can walk into one any time you need to do some paperwork, etc.  

Regional and local banks will often offer your better deals on interest rates, etc., but may not have ATMs all around the country.  

Online banks will generally offer the best deals, and the best online banking, but have few or no physical branches.  The other banks also have online banking, though the available features often lag behind the online banks.  

Examples of Mega Banks:

• Mitsubishi UFJ Bank (MUFJ)
• Sumitomo Mitsui Banking Corporation (SMBC)
• Mizuho Bank
• Japan Post Bank (JP Bank) - Run by the post office
• Resona Bank

Examples of Regional Banks:

• Chiba Bank
• Yokohama Bank
• Tokyo Star Bank

Examples of Online Banks:

• Sony Bank (Moneykit)
• Seven Bank (Run by 7-11)
• Rakuten Bank
• PayPay bank (Previously Japan Net Bank)
• au Jibun Bank
• Aeon Bank

Credit unions are a thing, they are called Shinyokumiai, or "Shinkumi" for short.  They are not so common, though.  

There are also so called "Trust" banks in Japan, which we will cover in the future.  

Investment banks are also common, usually being linked to a "normal" consumer bank.