It sounds like you're running into a crash issue with Koikatsu (or Koikatsu Party). Here’s a concise fix guide:
output_log.txt in the game folder.KKManager → go to Fix/Update.Many "crash fix" downloads on sketchy sites are actually just instructions or registry cleaners. koikatsu crash fix
Community forums (like Reddit's r/Koikatsu) can also be a valuable resource. Other players may have encountered and solved the same issue you're facing. It sounds like you're running into a crash
If none of the above steps work, you might consider uninstalling and then reinstalling "Koikatsu." This can help if the issue is due to a problematic installation. On startup → check output_log