To easily gain PP, on a day when you get a PP bonus, equip a Beckoning Cat (PP +20%) on a high level (80 to 100) character. Go to Duel Coliseum Falcon or Invincible Course. Take one Black Mage (increases secret bonus battles), one Ranger (increases value of awarded medals), and, for insurance, one White Mage (restore HP to full after every battle). Using the x2 medals you get from the bonus battles (the ones marked "?"), you should be able to quickly build up to 999 medals. Once you are at that point, use the Exit Card, and cash in your PP. In the Falcon Course you will get 2 PP per medal, and in the Invincible Course you will get 3 PP per medal. This in addition to the 48 PP per fight will result in you getting thousands of PP rapidly.