The calendar schedule (where each girl is at each time) can be totally ignored.
Also, you can unlock almost everything in less than 2 weeks, which should be your first goal.
Do not waste time doing H stuff if you do not have the H powerup. Seriously.
What I recommend if you dont want to grind it all over, is doing what I'll write below, and make a separate save for that state as to make it your starting point.
Game is too grindy tho, some animations are 10/10 (like reverse CG), but most arent.
Also game suffers from lack of CG or reward from clearing it.
Honestly, overall is like a 3/10. Wish we got more art like the one in the title screen in between levelups. Would totally elevate it to at least 6/10.