Just starting this, and I think the idea is really interesting. That said, it's pretty confusing. There's a lot of characters, they all look very similar, and none of them are really introduced. It also skips a lot back and forth through time (not just between the 'fantasy' world and the 'real' one, but also between times in both) so there's no real chronological flow, so you need to pay attention to the month at the beginning of the chapters to tell when it is.
Edit: Ok, it gets clearer later, just don't get turned off before you get through chap 3.
Edit 2: This is my new favorite manga. It's awesome. Going to binge it.