Peppeti Rosseti's autograph
At the hotel in the begging of the game, get to the floor with the battle system just outside of the lounge to the right, near the man standing in front of the door being blocked. Go past that and the next door will hold a brief intermission sequence. You will get Peppeti Rosseti's autograph on the back of your shirt. It will remain there as long as you wear the shirt.