Inner Tower is where the selected Regulars climb the Tower. The Ruler of each Floor decides on a series of tests, the specifics of which are decided by the Test Director and then held by Test Admins and other staff. Regulars must pass all of the tests on a Floor and then they go up to the next Floor. The only exception is the 43rd Floor where there is no Guardian because Enryu killed it. So, everyone has to take the road in the Middle Area to reach the next Floor.