You might not see the system because you may not be playing in hard mode - it's a hard mode exclusive system requiring extra management to make hard mode more difficult, yet fails spectacularly at doing so because the balancing for it is all over the place throughout the entire playthrough and all it really does is slow general progress to a crawl at around the halfway point of the currently existing story.
When it first released I was hoping it would be getting revised, but nope, it is just a means to an end in order to drag out playtime massively.
To nag on hard mode for a bit, the gameplay rewards for playing on it are just... not worth the hassle, really. The aforementioned mood system in place provides you with bonus points for the girls stats if they are at a high mood and I am honestly flabbergasted that such a weak "reward" even got a pass in the first place: It is entirely pointless, given that the mode forces you to spend time with each girl regularly, meaning their stats are going to grow naturally over time regardless. The double money and extra resources when playing with disabled rollback sounds nice when starting out, but means very little because you will be burning through all of those extra bits crafting gifts to increase their mood maximum or to fix their mood if it dips too low and they refuse to talk to you, which can also halt progress.
Not to mention that the timewindow of 2 days per girl before they start losing mood points is simply too short, given you only have 4 actions a day really. Split upon the entire cast, this becomes a massive problem by the time the cursed ones join the Manor, simply because by then you have next to no time left whatsoever to do anything other than keeping each girls mood up or take the penalty and have them stew at the sidelines while you do all of the auxilliary content. Even worse, for some assbackwards reason this system worsens once a girl becomes your actual lover, increasing the penalty instead of decreasing it - which would make more sense.
I really, really tried playing through the game in hard mode, on multiple occasions since the system got revised, but honestly it feels not worth to even bother with it anymore. By the time the story reaches the moonstars it becomes simply too much to bother with this ungodly amount of micromanagement getting in the way, so I bit the bullet and skimmed through the different scriptfiles until I found the section that handles the loss of mood points and just altered the values for each girl to be 0 across the board, technically disabling the system from getting in the players way.
