You know, even though you could rag on this manga for being harem, the truth is that it has excellent character interaction for such a large cast. More than this, what many people don't seem to be noticing is that it does not simply follow the idea of the idealized hero on a quest to save the world. It is the story of that hero's son and him just trying to help his friends and village be safe, not the whole world or some generic shit like that. Also, he is really just some kid in his fathers shadow trying to clean up the mess left behind, he is not even the biggest hero in the manga, its his dad that you don't even see.
tl;dr story is fairly original, even if it is harem.