A man loses his life in a “technobreak” (over-m*sturbation) and wakes up in a strange room. There he meets a beautiful woman of his fantasies who calls herself the Goddess of Fertility. According to the goddess, she wanted a “mature, unadulterated soul (i.e., the soul of an elderly virgin)”, and the man’s soul matched exactly what the goddess sought. The goddess said that she wanted him to reincarnate as a handsome, well-endowed, slim macho man in a world devastated by the evil gods, and, together with her blessing of fertility and prosperity, help her revive the world. In a nutshell, his task was to help repopulate the world. And as a rehearsal, he and the goddess had an affair right away.
It’s a classic story of an elderly virgin reincarnated as a handsome cheat-like being. He tries hard to have children of various races while solving their problems left and right.