Each Persona game has a different plot.
In Persona 5, a weird app suddenly gets installed in the MCs phone and it allows him to enter a palace - which is pretty much some kind of alternative dimension which features the twisted desires of a certain individual.
You pretty much go through the game defeating these palaces in order to change the heart of the person. It's a bit hard to explain but after defeating the person's palace, results in the loss of those twisted desire in the person (desires which are the primary reason for their unjust deeds).
The MC, together with his team btw, are mainly high school misfits but their hearts are good. MC, for one, is someone who lead a pretty ordinary life until he tried to step in and defend a woman from an influential guy who turned the tables on him and accused him of assault. ;;
yorunaka rolled 3d6 and got a total of 10:
3, 5, 2