Apologies for the post I made on the last thread, didn't see the link until now. I might be able to help with this. Are you using the Sakura Archives version of the games? I have legitimate physical copies of those titles and have worked in the fan translation space before. I have a feeling this is a text encoding issue, but might not be present in the newer versions of the titles as they are updated to work on modern OSes and possibly(?) have less text encoding issues.
Thank you. I was using the Sakura Archives version for Onsen Hen.
If it helps, I've been using
You must be registered to see the links
due to its wider compatibility and importantly the ability to import/export script files rather than working in the GUI itself.
While it wasn't the same issue, we similarly had problems with trying to insert text into Time Paladin Sakura when it came to different widths of characters when testing different old Circus titles, that one without a Sakura Archives release. It might be something shared in the older engine?