To get this one simply select 'The Devil's Kiss' game option from the main menu and play through it. It's a pretty funny satire of terrible 'visual novel' games and it should take you about 10 minutes to get through. There is a gameplay benefit
along with a couple of hints that can be applied to areas of the main game, so it is worth checking out.
I think this was initially buggy when the game first released but has been fixed in the September 2020 patch.