Other than the tradition that the kimon is to be avoided, another theory says that because it is the direction that spirits pass through, or the direction where the sun is born (the life gate), people have to guard their pure energy.
鬼門は忌み嫌われるという云れの他に、逆に神々が通り抜ける方角、あるいは太陽が生まれる方位（生門）であるために清浄の気を保たねばならぬという考えもある。