Japan taxation of US 401k account dividends

[staretunnel]

I did some searching on this forum but I wasn't quite able to find an answer to my question.

I am a Japanese tax permanent resident, so I'm taxed on global income. I understand that I need to pay taxes on the dividends and capital gains in my US taxable brokerage account, but I don't quite understand how my 401k retirement account is taxed in Japan.

Do I need to pay taxes in Japan on dividends in my 401k account? What about if I trade in my 401k account, do I need to pay taxes on capital gains?

[captainspoke]

From my reading on the JapanFinance sub (reddit), IRAs (tho they are a grey area tax treaty-wise) are treated somewhat favorably--no tax until you start making withdrawals.

A 401k may be treated the same way. Search/ask at https://www.reddit.com/r/JapanFinance/