This series is worth a look if you like style of anime. The following is a brief synopsis of Juuou Mujin no Fafnir.
With the sudden appearance of the monsters that came to be called Dragons, the world had completely changed. Before long, within the human race supernatural girls with the power of the dragons, called “D,” were born. The secret existence of the only male “D,” the boy Mononobe Yuu, was forcefully thrown into the school where the girls of “D” gathered—Midgar, where he saw the naked body of one of the students, Iris. Furthermore, meeting his long-lost sister Mitsuki, Yuu seems to have …read more at: MyAnimeList
Article Source: MyAnimeList
… the following video is a PV for Juuou Mujin no Fafnir