[Nano Machine] Suggest me something better please !

I was currently reading Nano machine and I reaallly liked the plot but I got to know it has harem in it (which is fine for some people but i am not a fan of that) so I am dropping that. It was really good why did the author had to add harem in it, so unnecessary. Anyways, Can someone suggest me something of the same calibre please??? < preferably without unnecessary fan service >