There are plenty of comprehensive guides out there as to how exactly to do this, but those are too long for here. However, I can offer some notes that will hopefully make things easier.
- Once you are free to move around Tokyo, if you press
, you'll bring up your map. The little blue cards indicate that a confidant is at that location. If you press
while hovering over the location, it will tell you exactly which confidants are there. More importantly, on this screen, you'll see one of several icons next to the confidant's name indicating what will happen if you meet them.
A greyed out card indicates that you've not earned the first rank with that confidant. A Blue card indicates that you can meet with the person, but they will not rank up this time. A blue card with "UP!!" next to it indicates that they will rank up during this meeting, and any points made during the interaction will go to the following rank. Finally, a blue card with "MAX!" next to it indicates that the confidant has been maxed.
- If going for this trophy, try to rank up your confidants evenly. This won't always be possible, and you should almost always take an opportunity to level up a confidant over doing something else, but you should rank up evenly when possible. This will maximize your potential number of confidants you can interact with at any given time (since they'll max around the same time), which will, in turn, minimize the number of times you will have no confidants to hang out with.
- There are a couple of exceptions here, and this will require balancing. Some confidants have a mission in mementos that must be completed around rank 7 or 8, and when you've reached that point, you won't be able to continue unless you complete that request. This is a priority since you want to minimize the number of times you enter mementos if at all possible.
- Similarly, there are some important cut-off points to be aware of and to work around. They are as follows.
- Two confidants, in particular, can save a lot of time. When you max out the Temperance confidant, she'll offer all of her services for free and offer a massage service that allows you to go out after visiting a palace or Mementos. The Fortune confidant also has an exceeding useful perk called "Affinity Reading," which gives you extra points with a confidant of your choice on the spot (for 5,000 Yen, unfortunately). These adhere to the same rules as other instances, and so you get an extra point for having a persona of the matching type. You'll want to rush to that level ASAP because it can save you many, MANY instances of visiting with confidants without ranking up.
- Once you've unlocked Affinity Reading, it may occasionally be worth your time to do something else rather than hanging out with a confidant who will not rank up, and instead visit the fortune teller a couple of times since it causes no time to pass. This maximizes your time.
- Sometimes the core party members will not want to hang out until a palace is cleared, so keep that in mind. However, this is definitely not true during palace 7, so feel free to level up your confidants before heading in.
- Finally, unfortunately, while you can carry over some confidant perks in NG+, progress does not carry. If you miss the mark, you will have to play through the entire game again since a couple of confidants only get their last rank during story events at the very end of the game.
If you are looking to finish all books and find all hangouts on this playthrough, it's definitely worth accepting invites to new places on your days off. In fact, these adventures usually result in 3 points for two different confidants, and can be useful anyway, though that would be highly situational.
Just a note, it's almost impossible (if not actually impossible) to do this on a first playthrough. You may just want to accept that rather than stressing yourself out, because stressing on a first playthrough can add way more than the 20 or so hours of a second playthrough.
Hope all of this helps! Good luck out there!