title_body: More than one chapter div in one epub file?
upvoted_answer: Kobo ereader devices have two different internal reading software.
  
  Ebooks downloaded from the Kobo bookstore are a modified epub format with the particular extension .kepub.epub, while if you sideload a standard epub from your PC it retains its original extension (.epub).
  
  By checking the extension of the files, the software automatically select the relative reading software (you don't normally notice many differences, they have some different internal features though).
  
  I had the same issue with page break html code and experimented a bit, and it seems that the .kepub.epub engine (the one used with books from the Kobo store) doesn't support it, so I think that there is not much you can do about it.
  
  A possible solution, like you have been suggested, could be to split the html file in multiple ones, exactly where you would have put the page break code. If you use Sigil or the Calibre internal editor you won't have to manually edit toc.ncx, contents.opf and all other files/references, because they will do automatically; it's an easy task, really.
  
  Please note that books bought from the Kobo bookstore are stored inside the device database and not as individual files.