What you need
1. Residence Card (Zairyu card)
2. Small deposit of 1,000 yen
3. Some banks ask for personal seal, in others just the signature is enough
THE BELOW IS COPIED FROM A WEBSITE
https://www.japanvisitor.com/japan-travel/japan-residents/bank-account
Opening a bank account in Japan is relatively easy. You will need your Residence Card (Zairyu Card, in Japanese) and your inkan or hanko (personal seal), though a signature may be enough in some banks such as Citibank (now SMBC Trust Bank/Prestia). A small deposit of 1,000 yen is enough to open your account.
Walk into your local bank of choice and fill in the necessary forms. You will be given the choice of your 4-digit personal identification number (PIN) and receive a bank book (tsūchō 通帳), which you can use to update your account balance and transaction history in any of the bank's cash machines (ATMs).
You will be asked if you belong to a criminal organization, which is a new regulation. Your bank card and information on managing your account online will be sent to you in about a week or 10 days.
your bank book or passbook will include your account name written in katakana or rōmaji (i.e., English), the 3-digit sort code (misebangō 店番号 of your local branch and your 7-digit account number (kōzabangō 口座番号. When your passbook is full you can obtain a new one from the branch where you opened your account, or automatically if you are updating your passbook in an ATM at your local branch.
The most common form of bank account in Japan is a general deposit account known as futsū yokin 普通預金. Interest rates are presently extremely low in Japan.
After opening your account you will receive in the post your cash card, which you can use to make withdrawals in any of your bank's branches. If you make a withdrawal at the branch of another bank, which is not your own, you may be liable to a service charge. There are also out-of-hours charges for services outside normal banking hours of 9am-5pm weekdays, unless you have a Japan Post Bank account, where withdrawals are always free.
The ATMs in Japanese banks and post offices usually have an English and sometimes a Portuguese menu and instructions. You need your PIN number and can withdraw, deposit, update your pass book, check your balance and make transfers to another account.
Japan Banking Hours
Japanese banks are usually open Monday-Friday from 9 am-3 pm for counter services. Banks are closed at weekends and national holidays. ATMs are open longer - usually until 6 pm.