Check out one of these unofficial guides, they should have all the steps:
Freshman Wiki
Freshman Walkthrough
thank you dear
i think there is something wrong with the spreadsheet. CG20 in spreadsheet is CG21 in the game's gallery, and CG21 in spreadsheet is CG22 in game, so i still need to unlock the real CG20.
For that CG, spend the night solo, at the end dance once, drink until you're visibly tipsy, then dance again. It should unlock then.
thanks
