One is an angel who embodies all the best and best qualities in the world, and the other is a devil who embodies all the worst and darkest flaws in the world.
Unexpectedly, a mortal mirror sucked in angels and devils, the angels were polluted by sewage, and the devils were washed by holy water.
Become a mortal, or a pair of biological brothers?
Everything seems to have made a small mistake... The gears started to move backwards...