Kichiku Megane

The story follows our protagonist Katsuya Saeki, and his life as an unsuccesful salary-man going nowhere...until one day, he is approached by a man in black, offering him glasses that will change his life from the moment he wears them.

From then on, Katsuya's life is determined by the role the glasses play, and whether he wants to give up on his current self, to be the brutal, but succesful man he could be, or stay as the incompetent but caring man he is.