Where the main character and one of the lead/major characters of the story interact with each other, athough they having differing position in society. and is a prevailing theme in the story.
 E.g rich and poor, or loner and popular
Just like how everyone adored heroes in their childhood, a certain young man adored those powers hidden in shadows. After hiding his strength and living the mediocre life of a mob character by day while undergoing frenzied training by night, he finally reincarnates into a different world and gains ultimate power. The young man who is only playing at being a power in the shadows, his misunderstanding subordinates, and a giant organization in the shadows that gets trampled…. This is the story of a young boy who had adored powers in shadows possibly eventually reigning over the world of shadows in another world.
Office worker Leon is reincarnated into a particularly punishing dating sim video game, where women reign supreme and only beautiful men have a seat at the table. But Leon has a secret weapon: he remembers everything from his past life, which includes a complete playthrough of the very game in which he is now trapped. Watch Leon spark a revolution to change this new world in order to fulfill his ultimate desire…of living a quiet, easy life in the countryside!
Zhao Yu used to be a little ruffian who fought recklessly without any morals and bottom line, after being framed and sentenced to a lethal injection death penalty; Zhao Yu woke up reincarnated to a parallel timeline, where he’s no longer a criminal, but a Key Case Investigation Team agent. The change from a criminal to a police officer had thrown Zhao Yu off and had him wreak havoc for the first few days in the station. But with the help of a mysterious “Miracle system,” Zhao Yu was able to embark on a new life where his goal is to solve the unsolvable cases and make amends for his past life’s mistakes.