That was one of the guesses, yes. But, if possible, it would’ve helped if this fact was somehow indicated to the user like with the main girls where it says there’s nothing more in the current version instead of a hint. Perhaps side girls should also have a similar page. At the very least, you could notify the user at the end of the last event with a girl, in this case for example at the end of the library, just give a notice to the user in the conversation text box that this is the end for the current version.
Also, another feature request I’d have would be being able to export and import saves. You do warn the users when loading the game that their save will be lost if the game is uninstalled, so I’d like to back the save up, though I’d want to handle that myself without builtin services.