Manga Ubau Mono Ubawareru Mono

Seto Yu was an ordinary 12-year-old boy who was constantly subjected to extreme abuse by his father. However, one day he will be transported to an incredible world that has the mechanics of a video game, after death at the hands of his father. Here he discovers that he has a unique ability that allows him to steal the skills of other people in order to use them on his own. He begins to use his incredible special power to take revenge on all those who mock him, as well as in order to get a harem of beautiful girls. They all love him incredibly, although he himself shows absolutely no interest in them. Their love surprises him, as he is an ordinary skinny teenager.