How does double and triple taxation work for index funds?

I’ve recently started looking into investing in Japan and had a few questions regarding how double / triple taxation works.

The [retirewiki.jp](https://retirewiki.jp/wiki/Japanese_global_index_funds#The_triple_taxation_problem) states I need to pay:

1. Withholding tax paid to the country of origin
2. Japanese dividend tax

Let’s say I’m enrolled in NISA and I buy stocks for Tawara No-load Whole World.

I’m assuming point 2 is null, due to NISA?

But what happens with point 1?

For example [sony bank](https://moneykit.net/visitor/fund/fund_notice/notice_JP90C000CMK4.html) states ~0.099% expense ratio (btw what’s the difference between 信託報酬 and 実質信託報酬 ??) and 20% / year return over the last 5 years, for the above index.

Do these values already include the money lost due to point 1? If not, how much should I expect to pay?

How about the case of triple taxation where I buy something like the SBI Whole World Index that also has to pay 10% in the US? (I’m not a US citizen in case that matters)

by tirafesi