In doki doki mode, when you attempt doki doki mode with the same person in one playthrough, you will find that you will accumulate stars. after accumulating so many stars the girl will be marked by a star with their name when they are supposedly maxed out. May be relevant in finding all profile info for each girl.
Confirmed: There are three teachers in the game. After getting 3 stars for each teacher the achievement popped. EVERY girl probably needs to targeted about 3 times in doki doki mode to complete the girl's profile in the class roster. Even though there are multiple profiles, only the 3 teachers are required for the achievement.
GOD score can be achieved in Score attack. From the main menu, after beating going through all girls routes, choose the first menu choice, then the last menu choice, then the first menu choice. It will allow to ti run through all the previously played routes without the mini games or the boss fights. If looking for particular girls to finish their profiles, you can choose each girl's individual routes below the first choice of the final menu.
Biggest mistake I've been doing since playing this game. When quitting out of game, you'll have an option for X and B. It is asking if you want to save your progress. X means no. B means yes. Always pick the B button when quitting out.
Titles are gained during a specific rank. Rank is earned after breaking a score threshold. You can only earn certain titles after becoming a particular rank.
Title guide can be referenced here.