Luther Alexander is the first character you meet in the game as part of the Introduction, where he introduces you to actions and how they work throughout the game. He works at So Chic in Downtown LA, first as your manager and later as your employee. After completing the Take Miami goal, your character will stop working at So Chic and Luther will ask your character about the new job whenever you enter the store. If you answer that you're not enjoying it, he'll be thrilled.
Later in the game, you will be able to purchase So Chic. Even as the owner, you can still earn Cash through working a shift by speaking to Luther, who will treat you more nicely and refer to you as 'boss'. You can also ask him for advice regarding the game.