There are loads of characters that you can recruit and each one has his or her own story arc, but the maximum amount of characters in your party is 6. (playstationing.com)
Not only are you allowed up to five characters in your party at once but you are able to select your formation, which adds offensive and defensive elements to your strategy. (gamefreaks365.com)
You may often have two different versions of the same character in your party thanks to all the time traveling fun in the plot! (brickstolife.com)