Inukami!

Inukami are demons with the apearence of a dog which protect the humans from other demons. However, Keita, a descendant of a historic Inukami-tamer family, lacked their gift, and so he was forsaken by the family. One day, an Inukami named Yoko came in to his life, and from then on, Keita's life would never be the same. Although Yoko was really beautiful, she was a problematic Inukami that no one had been able to control, and from that moment the endless train of Keita's embarrassments was without end.

Synopsis from Anime News Network