Exploring Palaces isn't the only way to level up in Persona 5 Royal. Shortly after the first arc, the Phantom Thieves will be tasked with completing requests from the public. While not a mandatory part of the story, taking on Mementos Requests is needed to complete most of Joker's Confidants. As the Phantom Thieves' reputation grows, so does Mementos. Players should make a habit of going into Mementos during one of Joker's off-days.