From Go! Comi:

In today's world of computers and cell phones, few people have time for superstition and ghost stories, but that doesn't mean that they aren't real! Amane Kamori is a powerful medium from a remote village in rural Japan. Her guardian is Hyoue Inugami, a demon dog whose powers are literally fueled by her kiss! Together they protect humans from vengeful spirits and bring peace to the dead.

But when Amane's family moves to the big city of Tokyo, all the magical power in the world can't help her survive high school! Her chilly demeanor and lack of social graces make her a campus misfit. Popularity comes much easier to Hyoue, whose sexy good looks (in his human form) bring him lots of female fans. But Hyoue's lapdog loyalty to Amane only leads to more woe, as jealous classmates can't understand what he sees in her. If only they knew?