...I just read chapter 27 on onemanga, too. I like it a lot...gotta love Natori!
Anyways~
I figured I should support the official release of some anime and manga by buying the first volume of the manga or at least the first season of the anime. I am such a saint.
So to answer your question, they only translated 2 volumes thus far, and Borders had volume 1, which was the one I wanted to buy in the first place.
(It was translated by shojobeat...I didn't know that it was considered shojo just because it was written by a girl)