Well, to resume, the male protagonist is in a world where, after a war used almost all ressources of earth, every conflict is resolved tought games. The MC came back to have a normal life and to see his sister again after 5 years where it's suggested he was doing high level games who disgusted him from this world. Now, he want a normal life and enter the same school has his little sister who reek of brocon raping but the school work with the same games blahblahblah i will not spoil you, but see my first comment, its almost the same thing as another manga.