Rick
Rick is a screenwriter. He grew up with his family; his father and his two brothers, one that died before growing up and the other that is having a hard time. Rick searches for something greater in life than what he has been living and finds his road through several women he meets. It is hinted at the end of the movie that he is the Knight of Cups, a lost prince that is on his way home.
The King of the East
The King of the East was a man that had a son. His son, the prince, went out looking for a pearl, wishing to give it back to the King in order to please him. However, this didn’t work out, as he drank from a cup he was given, and then forgot about his kingdom, father and mission. This is why the King was in despair. However, the King made a plan and sent out messengers to help him find his way home.
Isabel
Isabel is the last woman that is presented in the movie. Just like the others before her, he is wise and knows a lot more about life and the reason for it than Rick seemingly does. She is beautiful and young. She is the one that finally leads him on the road towards the East, towards his father, his kingdom and his purpose.