Yes the base game and the translation only
Did you delete the Summertime Saga folder of saves in your %appdata%/RenPy folder when you deleted and before you reinstalled? If you have old saves that were run under mods/patches - those may cause issues.
Because if it is purely the game and the translation, it shouldn't reset the translation like that. The i-patch causes issues with translations similar to what you are stating. (as well as using saves from previous versions if you had used certain mods/patches during them)
If you're wanting to give another option a try - you could go over to srksrk 68's Naughty Tribute Mod. It has ways of using online translation that may stick with you.
But again, you would want to delete the game folder, delete the %appdata%/RenPy Summertime Saga save folder and then reinstall things.