1) Download font "mplus-1c-regular.ttf" from https://drive.google.com/drive/folders/1y2rgvyjZnecB5tY3_uLvf2-6I-MJtf_1?usp=sharing
2) Put the font in "SteamLibrary\steamapps\common\Hoshizora no Memoria -Wish upon a Shooting Star-\fontfix" folder (Confirm the file replacement);
3) Install the mplus-1c-regular font (Confirm the font replacement);
4) Restart ur PC.

After that, only capital letters will be used in all dialogues.

If this did not help and the letters remained lowercase:
1) Make sure you restart your computer after installing the font;
2) Close all open programs and applications;
3) Open windows fonts folder "C:\Windows\fonts" and make a backup copy of all fonts;
4) Remove all fonts that windows will allow you to remove from this folder;
5) Restart ur PC;
6) Install the mplus-1c-regular font;
7) Install all fonts from the backup without agreeing to replace existing fonts;
8) Restart ur PC.

After that, everything should definitely work. If it didn't work, then you made a mistake somewhere and you have to repeat all the steps again.