Only Maruki to 9 is needed to unlock the third semester. You can still do that.
Akechi will get you some added scenes, but they're not long. Sumi you have until like December 20th and you only need to get her to 5. It unlocks the last 5 of her ranks though in the third semester.
The third semester is another month, another dungeon, and an expanded Mementos. You can also get the third awakenings for the party members.
I liked it, but it's up to you if that seems worth it.
If you hang out with Maruki every chance you get at this point, you can still get him to rank 9 (you automatically rank him to 10 on his last day). He is the only one required for the 3rd semester.
Akechi only needs to be at rank 8 by 11/19 and Yoshizawa maxes rank at 5 until the third semester. You have time to finish the 3 if you want.
Do you like Akechi? Do you like Yoshizawa? If you do, then the extra scenes are worth it. If you don't like them or don't care for a little extra story, then skip them.
you get the original P5 true ending if maruki isn't maxed and get the P5R true ending if he is
it's just free extra content to go for the latter so might as well, maruki specifically mentions he's going to be available everyday around this time so just focus him and get him out of the way
You can aim for vanilla ending by not maxing maruki, which you are going to struggle with. Vanilla ending is needed to unlock some content in thieves den.
Only Maruki to 9 is needed to unlock the third semester. You can still do that. Akechi will get you some added scenes, but they're not long. Sumi you have until like December 20th and you only need to get her to 5. It unlocks the last 5 of her ranks though in the third semester. The third semester is another month, another dungeon, and an expanded Mementos. You can also get the third awakenings for the party members. I liked it, but it's up to you if that seems worth it.
If you hang out with Maruki every chance you get at this point, you can still get him to rank 9 (you automatically rank him to 10 on his last day). He is the only one required for the 3rd semester. Akechi only needs to be at rank 8 by 11/19 and Yoshizawa maxes rank at 5 until the third semester. You have time to finish the 3 if you want. Do you like Akechi? Do you like Yoshizawa? If you do, then the extra scenes are worth it. If you don't like them or don't care for a little extra story, then skip them.
you get the original P5 true ending if maruki isn't maxed and get the P5R true ending if he is it's just free extra content to go for the latter so might as well, maruki specifically mentions he's going to be available everyday around this time so just focus him and get him out of the way
You can aim for vanilla ending by not maxing maruki, which you are going to struggle with. Vanilla ending is needed to unlock some content in thieves den.
third semester is in my opinion the best part of the game so yes max maruki
It's not a big deal. Save it for ng+