I think that almost all players in the West don't care about it, but it is just a caution for the Japanese players.

Yakuza 0 GOG version does not have the Japanese text (Although the game page on GOG says so) and can not change it in the options menu.
Even these language files don't exist in the game folders.

The Steam version has the Japanese text, so I am slightly disappointed.

I looked at Yakuza Kiwami 1 too, and it seems the game doesn't have the Japanese text either.

Both Yakuza 0 and Kiwami have separate Japanese offline installers (see attached screenshot). I haven't had time to test it yet, but with those the games should be completely in Japanese.
Not sure if and how changing to the Japanese version works with Galaxy.

Oh, that's a relief!
I'll check whether it works (or not).

EDIT: it seems worked correctly.Thank you again!

Hello, sorry to bother you, where did you find this page to download the Japanese version? Please tell me, if you can, please share the Japanese version of the patch with me, my country is not available to buy this game, I still got it through a friend

I just followed DoctorGOGgles's suggestion.
Click on My account, Games, Yakuza 0, and then, click on the Language: English to change it into Japanese, and then download the offline backup game installers.

"my country is not available to buy this game,"

Really? I just brought the Y0, K1, and K2 bundle on GOG in my country, aka Japan too.

QAQ i study in China now QAQ I'm sorry to bother you, but I'll play in English first and revise it when I get back to Japan

I asked my friend to log in to my number and download a copy to me, no need to bother you, sorry to bother you