-Learn a level one spirit or nature magic that can lower the enemies status, then go someplace that has weak enemies such as Jellys and cast the spell until your MP is depleted. You will get around 200 PP by casting with WIS 255, allowing you get about 5,000 PP in an hour.
-Two or more people are required for this trick to work. Get a level 1 Jelly. Enchant, then tame it and go into Macgyver Castle. Make a camp. Note: Only the person making the camp can click on the lock. Set the Jelly free, then RIGHT CLICK on the lock as fast as possible (at the top right of the screen), while the person that wants the PP attacks with his normal weapon (no spells). Keep doing this until you have the desired amount of PP. If your Wisdom is 200+, you can easily gain hundred of thousands of PP in a very short time.