"The English version by Mastiff introduced a bug that causes unlocked costumes to not carry over into New Game+. It also suffers from various typos, spelling, and translation errors, which can be fixed." www.pcgamingwiki.com

Source: https://www.pcgamingwiki.com/wiki/Gurumin:_A_Monstrous_Adventure#Fix_typos_and_other_script_errors

You just need to replace the files in your game location

Links:
wwwmediafirecom/file/m7t7x5tf8mu2r1h/Gurumin_Script_Fixes.zip
or
https://archive.org/download/GuruminPCFix/%21Gurumin%20Script%20Fixes%20%28fixes%20typos%2C%20speech%20bubble%20glitches%29.zip

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BONUS:
My FOLDER in Google Drive for backup files with some others mods and more for this game:
https://drive.google.com/drive/folders/1RN4EIppACbPDNHgjhBhDLw3y6TeJSmh5?usp=sharing

Pls put "." in the link when download, cuz I need to remove them to post the link here.