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 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, who possesses an ancient form of magic called Dragon Slayer magic, which grants him control over and protection from fire. Natsu offers membership to Fairy Tail for Lucy, which she accepts. Lucy forms a team together with Natsu and Happy, as well as Gray Fullbuster, an ice wizard with a strange habit of stripping, and Erza Scarlet, an armored female wizard. The five go on missions for their guild together, battling illegal guilds known as dark guilds, as well as demon servants of the ancient dark wizard Zeref.
During their adventures, Fairy Tail wages war with Phantom Lord, a rival wizard guild commissioned by Lucy's estranged father to destroy the Fairy Tail guildhall and return Lucy to him, revealing her to be a member of a wealthy family. While fighting Phantom Lord, Natsu encounters Gajeel Redfox, another Dragon Slayer who Natsu is surprised to learn had been raised by another dragon, Metalicana, who disappeared the same day as Igneel. Fairy Tail defeats Phantom Lord, prompting Lucy to cut ties with her father completely. Lucy and her friends go on a vacation while their guildhall is being rebuilt, only for Erza to be kidnapped by her former childhood friend, Jellal Fernandes, who had been manipulated by the wizard Ultear Milkovich into helping her revive Zeref using a construct known as the R-System. Jellal attempts to use Erza as a sacrifice for Zeref, but Natsu rescues her, destroys the R-System, and defeats Jellal, who disappears and is believed to be dead.
Lucy and her friends return to their newly renovated guildhall to find that Gajeel has joined Fairy Tail. After dealing with Laxus Dreyar, a renegade Fairy Tail wizard and grandson of Fairy Tail's master Makarov, the guild is faced with an alliance of three of Fiore's most powerful dark guilds known as the Balam Alliance. Fairy Tail is commissioned to fight one of the Balam Alliance guilds, Oración Seis, by forming their own alliance with wizards from the Blue Pegasus, Lamia Scale, and Cait Shelter guilds, the last of which is represented by Wendy Marvell, another Dragon Slayer whose dragon guardian Grandeeney went missing. During the mission, Jellal is discovered to be alive after Oración Seis forces Wendy to revive him. However, Jellal suffers from amnesia and helps Fairy Tail defeat Oración Seis instead before he is arrested for his previous crimes. Afterward, Wendy's guild is discovered to be an illusion created to care for Wendy after she was abandoned by Grandeeney, leading Wendy to join Fairy Tail.
