Japanese citizen living abroad worried about old Japan bank accounts — what should she do?

Hi everyone — looking for some advice or reassurance about a situation with my wife’s Japan bank accounts.

My wife is a Japanese citizen but has been living and working abroad for many years and pays tax where we live. She still has several bank accounts in Japan that are registered to her parents’ old address. She inherited the family house, which is now in her name. The house is always empty, but she continues to pay the utility and municipal tax bills regularly from her Japanese bank accounts.

She recently learned that banks may require non-residents to inform them of their status, and now she’s very worried because she hasn’t done that. She’s also concerned because she’s occasionally withdrawn money herself when visiting Japan, and a few times gave her bank card to a relative to withdraw funds for house maintenance. There’s around ¥4.5–5 million total across the accounts.

She has no income in Japan at all — no rental income, no interest, no salary, nothing. Her only income is from work abroad, and all her tax matters are fully up to date there.

I’d really appreciate advice from anyone familiar with Japan’s banking or residency rules:

1. Is it a problem for a Japanese citizen living abroad to keep bank accounts registered to an old Japanese address?
2. Is this usually just an administrative or compliance matter with the bank?
3. What practical steps should she take to update or regularise things (e.g., contact the banks, switch to non-resident status, required paperwork)?
4. Have others had experiences with Japanese banks checking residency or freezing accounts if not updated?

Thanks in advance for any help or insights — we just want to make sure everything’s in order.