Hello! How are you?
Please keep in mind that I do share updates with GGG, but they are the ones responsible for processing and publishing them. This is why I usually recommend purchasing the products directly through itch.io, since it is much easier for me to manage everything there and I have much more control over updates and distribution.
In fact, for the Ultimate Gacha Minigame plugin, I offer users the option to link their itch.io account with Steam.
You can do this easily through my official website here:
https://undermax.online/undermax/plugins_steamconnect/
Regarding the Japanese translation, all of my plugins on itch.io are managed in English. Everything related to the Japanese translation is handled by GGG, so unfortunately I do not have direct control over that part.
If you need anything else, feel free to contact me.
Best regards!