Can Japanese banks receive payments from outside Japan via IBAN?
For instance, Japan Post Bank does not accept IBAN, so sending money to a Japan Post Bank account is very complicated.
Is there no Japanese bank that accept payments via IBAN?
Basically speaking, Japanese bank accounts are identified by three numbers:
The four digit Bank number. For example 0005 is Mitsubishi Tokyo UFJ Bank
The three digit Branch number. For example 001 = Main branch for Mitsubishi.
The account number. This is your account number.
Your ATM Cash Card and passbook will have these numbers on it in the format XXXX-YYYY-ZZZZZZZZ.
When you use an ATM to send money to someone else (like your landlord) you but in these three numbers or use the search feature instead for the first two. This works the same whether you are talking about Mitsubishi, Mizuho, etc. The only thing to note is that while real banks use locations for the branch number (i.e. Ueno branch, Marunouchi branch, etc.), online only banks like Sony Bank (MoneyKit), Rakuten Bank, SBi, etc. use fake locations like colors, etc. This doesn't matter much though.
Japan Post bank is technically not a bank and uses a totally different numbering system, though recently they have come up with a strange formula to convert your JP Bank account number into a normal bank account number so you can send payments to it as shown above).
All of this is basically for domestic transfers only, though. If you want to transfer money internationally, there are two basic ways:
The official way. Go to your bank overseas, and give them the SWIFT code and account code for your bank (likely the branch code will be necessary as well). The problem here is that they will likely charge a high fee for sending the money, and your bank in Japan may also charge a high fee for receiving it! (In addition to any currency conversion fees). A second problem is that only the very major banks even have SWIFT codes.
Use a money transfer service that can handle both Japan and your other country. For example, you can use 2 Paypal accounts (Only in the direction of From Japan To overseas, though!), or you can use something like MoneyBookers
Either way IBAN is a European standard and isn't used in Japan.
If you just want to spend some money in Japan, the most convenient way is probably a foreign visa debit card. Or, you can use a foreign ATM card in Japan to withdraw cash and then deposit it into your Japanese account.