RenPy games have two separate persistent files. The first file is simply found in the folder you dowloaded under „game\saves“ and is called „persistent“.
The other one is under „C:\Users\user\AppData\Roaming\RenPy“ Just select the RenPy folder, find the „DatingSim389“ folder inside of it, and delete the persistent file that one has as well.
That should take care of everything :)