Bound By Hate (Gale) {Book 1 of the "Bound" Series}

BOOK ONE.
Fairy Tail is among many famous demon-hunting organizations in the kingdom of Fiore. Dedicating their lives to putting a stop to the demons' plague on Earthland, demon hunters specialize in their own techniques to taking down demons. Some used guns and swords, while others used pure brute strength to do the job.
Levy McGarden, orphaned as a child because of one of these demons, became a hunter for the Fairy Tail organization. She made it her life's mission to avenge her parents' death by killing the demon responsible. When the leader of Fairy Tail, Master Makarov, sends her team on a seemingly hopeless assignment, her life is forever changed by one fated encounter.
Gajeel Redfox, an exceptionally powerful demon known as a dragon slayer, crashes into Levy's life with a fury. Although neither of them know it, they will become closer than they ever thought possible, and Gajeel will lead Levy straight to her parents' killer.
Unfortunately for Levy, the demon she has been seeking for so long will be the only one she can't bring herself to kill.