Heya!

I've just recently bought the original series (http://www.mangaupdates.com/series.html?id=4876) and no I've found about this newer version (http://www.mangaupdates.com/series.html?id=48174)
By what i found out it is more or less the same story with some changes. Then on this website it says that it'sa sequel. Can someone who knows both tell me what exactly this is and if its worth getting if i already have the first one? @.@