Mementos has one main platform with a slant in the middle, similar to Meta Crystal, with two pass-through platforms over the center and the left side. A third platform with a cracked screen occasionally appears on the right. Trains periodically appear in the background, the set below the stage being able to damage fighters. If a fighter is hit by the front of a train, they will take much more damage than usual, and trigger a Special Zoom effect. Occasionally, a large triangle-shaped wall appears at the top or on the sides of the stage. The trains and the walls usually never appear at the same time, though they can appear at the same time when walls appear above the stage. When players run through the stage, they'll splash purple ink-like liquid with each step.
The stage's main design, based on Persona 5, uses a predominantly red color scheme, with star designs and black-and-white halftone motifs. If a song from Persona 4 or Persona 3 is playing, the color scheme changes to yellow or blue respectively, the respective primary colors for each game. The platforms change design to incorporate flowers and checkerboard patterns (for Persona 4) or clocks and triangular patterns (for Persona 3). Similarly, the backdrop changes to include rainbow-like streaks (for Persona 4) or a moon (for Persona 3). If Joker wins a match on Mementos in one of these alternate designs, his victory pose screen and victory music will match Mementos. Joker's Rebellion Gauge will also change color to match that of Mementos. If Stage Morph is on, the victory screen will reflect the most recently visited version of Mementos. If the match ends before Mementos is visited, the screen will have the default Persona 5 theme.
The Morganamobile occasionally appears in the background with a "meow" sound, dropping off the other Phantom Thieves of Hearts. When a fighter is defeated, they will occasionally call out in praise.