Zerø arc

The Tenrou Jade arc is the first (chronologically sixteenth) story arc of the Fairy Tail series.

The untold story behind the creation of Mage Guild Fairy Tail. In the year X679, Mavis Vermilion is left to fend for herself after a war takes the lives of those who reside on Tenrou Island. Seven years later, she encounters those who will title themselves as the founding members of Fairy Tail and those who will wrap the world in despair in the foreseeable future.

War of Epic Proportions
In the year X679, a young Mavis is reading a book in her guild, Red Lizard. Her master, Jezelf comes over and reprimands her for slacking off while she's supposed to be on cleaning duty. He hits her and bats the book from her hands, with the other guild members mocking her for hobby. The master then notices the shoes he bought for her, demanding she returns them as she is not worthy to have them. Even when Mavis pleas that these are her only pair of shoes, the master didactically orders her to return them at once. Later, as she young girl cleans, Zeira returns from school and gleefully greets her father. As he tries to offer her the shoes he retrieved from Mavis, Zeira rejects the distasteful footwear, stating they are dirty and unfit for her.

Mavis recalls of her past and how she was brought to the guild through working to repay the guild from monetary issues regarding her parent's debt, reminding herself of her parent's words of someday meeting actual fairies. Suddenly, huge explosions are heard outside the kitchen which Mavis comes outside to glance upon Blue Skull invading the guild. Mavis scurries through the chaos, locating Zeira, who is trapped under the rubble caused by the war. Mavis pulls her out and guides along with her to safety, which the brown-haired girl refuses her request as she was cruel to her. Mavis states she doesn't care about that as everything worthy to her resides in her heart. Relieved and in a change of heart, Zeira requests to become friends with Mavis before collapsing, deeply worrying the latter. Mavis later returns to the village, only to see the aftermath of the war left genocide, as everyone from the townspeople to the guild members were killed.

Seven Years Later
Seven years have passed, a group of treasure hunters arrive to the island. Warrod mentions the serene mood coming from the land, with Precht reprimanding him as they aren't here to play around. Yury arises from his slumber, who has no doubt that they arrived at the correct destination of where the Tenrou Jade is located at.

Trivia

 * The anime adaption of the arc premiers between the conclusion of the Tartaros arc and Avatar arc.
 * This arc is currently the only one featured after a spin-off and serialized in the Monthly Fairy Tail Magazine.