Black Mirror
Complete | Muhwa,Wrist | 2000 released
*SPOILERS* For those who don't get it: The author is making a point that they are the only ones in this world who aren't insane. In the world of the story, they are the only ones who know the truth. Everyone else is forcing themselves to do things according to what will make them likeable, acceptable, and less lonely - like the MC at the beginning of the story. But it only makes them miserable and empty, or worse yet, liars who hide their true intentions to keep up appearances but are actually jealous and malicious. Like the professor. The point the author is making is that the main couple finally accept themselves as they truly are.
Kansai Jin to Hukumen Satsujinki