That's doujinshi. It's basing it's character designs on the anime models (which were based on the illustrations for the novels). The official manga's characters look different stylistically (given they decided to try and expand the age base to younger audiences). So, the answer is: no.
The series had two manga runs. The first was canceled because the first artist for the manga was doing a h-manga project on the side. The second one has very drastic character design differences for the most part.