For the State events, it's required that you see/play each scene involving the girl at least twice. For a guide on what scenes each girl has, check the guide, link is in the 1st post of the thread, below the "Downloads" area.
Also to be able to see every scene both the MC (Main Character) as well as the girl in question need to have 70 points each, the only exception would be Mia, who has a cap of 35 atm. Of course there's a bit more nuance here and there but with the guide you shouldn't get lost and it also serves as a tally to know which scenes you already have done and which you haven't done. As for the Diary, haven't played this particular version so idk if each girl has that legend show after their State event or if it still only applies to Martha (believe it has been there since 0.15 dropped).
Also a couple of tips: Save in different slots, don't YOLO this shit and use the same saveslot for all the playthrough. I mention this cause there's certain scenes that end up locked depending on the State the girl ends up in, even the game notifies you to save in a 2nd slot in case you mess things up and need to go back to a previous point. The guide offers a description on which scenes are related to what State, so keep it in mind.
Accompanying this, whenever you get the Jules/Velvet event, keep a savefile during each of the events cause you can't repeat/revisit them, those are currently a one-time only event so if you wanna play them again, having a backup savefile during said event will serve you well.