If you are a foreigner without Japanese nationality and need to open a bank account at Mitsubishi UFJ Bank, you should take a look at this website:
Here are some tips from me;
1. You should bring evidence that you need to open an account at a company's instruction.
2. If you are not fluent, you should take someone who speaks Japanese.
The website above says;
Please prepare the below and visit the branch in person.
(1) Customers who are working in Japan (Residents)
- Residence (zairyu) card (*1) (we will check the period of residency in Japan, residency status, etc.)
- Personal seal (*2)
- Documents to confirm your Individual Number (My Number) (*3)
- Documentation verifying your working status in Japan
Ex.: Your health insurance card with the name of the company where you work, your statement of withholding tax with your company's seal, your employment contract, etc.
Note: In some cases, we may confirm your employment with your employer
The "Personal seal" refers to 印鑑（In-kan) with your name. This has to be made of wood or a similar hard material rather than a rubber stamp.
You can make your personal seal online or in person at a 文房具屋（stationary shop）.
At hankoya.com you can order your seal and receive it within two days, but the website is entirely in Japanese.
The MUFG website mentions you must take documents to confirm your Individual Number (My Number), but at a recent visit this was not needed. Instead, an American Social Security Number was requested.
As a new employee, you can confirm your employment with a business card and an email confirming your employment. This is to confirm that you are opening the account by company request, and that you are not involved in money laundering activities. Ideally, however, you should take a health insurance card with the name of your employer, your statement of withholding tax with your company's seal, or your employment contract, as mentioned on the MUFG website.