Instructions
Advance your starting characters to at least level 10. This will open the first group of new classes: Ninjas and Ronins.
Develop one character with a bow to Bow Level 3. This will open the Archer class.
Increase another character's Gun Level to 30 to open the Recruit class.
Increase all three types of starting magicians to level 5 in order to unlock the Star Mage. Then advance the Star Mage to level 35 to open the Prism Mage. When the Prism Mage is level 50, you will have access to the most powerful magician, the Galaxy Mage.
Make the most powerful classes available by focusing on working all your characters up to level 200. When all female characters reach that level (Cleric, Ronin, Knight, and Archer), you will have access to the Angel. When all the male characters (Warrior, Brawler, Ninja, Rogue and Scout) are level 200, you will unlock the Maijin class.