Fairy Tail(フェアリーテイル)

A 17-year-old celestial wizard named Lucy Heartfilia runs away from home to join Fairy Tail, a rambunctious wizards' guild whose members are infamous for their overly destructive antics. Along the way, she meets Natsu Dragneel, a boy who is traveling the land of Fiore together with his partner Happy, a talking cat, in search of his foster parent, a dragon named Igneel who had disappeared without a trace seven years prior. Shortly after their meeting, Lucy is abducted by a wizard claiming to be the famous Salamander of Fairy Tail to be sold as a slave. Natsu rescues Lucy and reveals himself to be the real Salamander and a Dragon Slayer, a wizard with the abilities of a dragon. Natsu offers membership to Fairy Tail for Lucy, which she accepts as she always wanted to be part of the guild.
Lucy forms a team together with Natsu and Happy, as well as Gray Fullbuster, an ice wizard with a habit of stripping, and Erza Scarlet, an armored female wizard. The five go on missions for their guild together and battle a wide variety of villains, which include: multiple dark (illegal) guilds led by an organization called Baram Alliance; demons created by an ancient, evil wizard named Zeref; Phantom Lord, a rival guild to Fairy Tail; Erza's former childhood friend Jellal Fernandes; and Laxus Dreyar, the renegade grandson of Fairy Tail's master, Makarov. The Fairy Tail guild also sees the inclusion of two other Dragon Slayers—Gajeel Redfox from the Phantom Lord guild and Wendy Marvell from the Caitshelter guild—who were both raised by dragons (Metalicana and Grandeeney, respectively) that disappeared on the same day as Igneel.
Later on in the series, several members of Fairy Tail, including Natsu, Lucy, and their friends, gather for an annually held examination on their guild's sacred ground of Tenrou Island, where they discover that Zeref has been living on the island and is being sought out by one of the guilds of the Baram Alliance, Grimoire Heart. Though Fairy Tail defeats Grimoire Heart, the incident summons the black dragon Acnologia, which attacks the island. However, everyone on the island is protected by the spirit of Fairy Tail's founding member, Mavis Vermillion, and reappears seven years later.