I know the story?

When I realized it, I was already in another world. Not just any world, but the world of a novel I had been reading recently. — A bit cliché, I’d say? A world ravaged by a demon that only the predestined hero could defeat. A hero who, as he progressed on his journey, formed an impressive harem. Wherever he went, he faced dangers and problems, but he also found opportunities that made him ever stronger. — You know what? Let the hero deal with it. I'm just going to live my life. That’s what I thought… until I discovered something the author had hidden and would probably only reveal at the end of the story. — …I hate that guy. — Description from novelcodex.org