Galuna Island arc

The Galuna Island arc is the fourth story arc of Fairy Tail. This arc includes Natsu and Happy wanting to go on an S-Class Mission, which is forbidden for Mages not of S-Class. He steals an S-Class request without permission, and drags Lucy and Gray along with him. Upon arriving on the island and being faced with a request more difficult than they initially thought, they discover another event that requires their attention: the resurrection of the Demon Deliora by an old friend of Gray's: Lyon Vastia. Natsu, Happy, and Lucy arrive at Hargeon Town, hoping to find a boat to take them to Galuna Island, the location of the request. But no sailor agrees to take them there, afraid of its curse. As they ponder their next move, Gray shows up behind them to take them back to the guild, threatening them by mentioning Erza's rage if they refuse.

Natsu still wants to continue with the mission and almost gets in a battle with Gray. As they prepare their Magic, they are spotted by the last sailor Lucy and Natsu asked. He calls out to the Mages, telling them that he is willing to take them to Galuna Island. Natsu knocks out Gray, who is distracted by the man's sudden reversal, and takes him with them for fear of him tattling on them to Erza. Along the trip, Gray, now conscious but restrained by ropes, asks the sailor why he let them on. He introduces himself as Bobo and reveals that he was once an inhabitant of the cursed island. Bobo shows them his demonic arm and questions their resolve. Meanwhile, at the island's summit, a sinister ritual is in progress.

When the team spots the island, Bobo suddenly disappears and, without his guidance, they are swept away by the waves. In the morning, they finds themselves washed up on the shores of Galuna with no way to leave. They decide to continue their quest, this time with Gray willing to help. By nightfall, they arrive at the village that posted the request and are greeted by the village chief and the villagers, who show them their problem by revealing their physical deformities akin to that of Bobo's. The chief, Moka, explains that the curse began since the moon turned purple a few years back, its Magic Power turning them into Demons. At that moment, the moon comes out, its light causing the villagers to transform into Demons. Moka then adds that they revert to their human forms with the arrival of the morning, but an unfortunate few stay as Demons. The villagers are forced to kill them to prevent them from harming others, his own son, Bobo, being one such victim, a fact that shocks the team. The villagers then beg them to dispel the curse, but Moka states that the only way to do so is to destroy the moon itself.