GM Advice: Set Expectations
Rule of the Day: set player expectations. If players build and campaigns are consistent, you had better start everything in the same direction. Players need know what it is that they will be doing so they can make goals that can be achieved. Become the greatest swordsman of France doesn't fit in a modern day Japanese high school. Becoming the world's greatest spy doesn't work if the game focuses on looting remote dungeons. Tim the Enchanter does not fit in a Gothic horror game. And the player who does this knowing the expectations does not belong in your group.