I bought mine from Barnes and Noble. I have also seen it at Amazon.com. But make sure you are looking at the light novels rather than the manga when on amazon because the covers are similar. Right now the volumes translated cover up to where the anime stops which is through volume 5. The six volume will come out in August. There was a translation somewhere on the internet but I think it got taken down because it was licensed by Yen Press.
does anyone know where I can find the light novel? (〜 ̄△ ̄)〜