Galuna Island arc

The Second floor and S-class Missions
Upon Natsu and Erza's release they continue their battle, which Erza wins in an instant. Shortly after the S class mages of Fairy Tail are introduced. Mystogan puts everyone to sleep before taking a mission and Laxus is introduced and shows is stubborn self by saying he is the strongest and event tried to push Natsu to come to the second floor and challenge him. Natsu then tried to go up but was stopped by Makarov and told that he is not yet ready.

Later Lucy asks what Makarov meant and Mirajane tells her that the second floor is where the S class ranked jobs are posted. Since S rank jobs can take the life of anyone who makes even one mistake, they are forbidden by anyone besides mages who Makarov approves. Lucy later returns to her apartment and finds Natsu and Happy doing intense workouts. She later learns that Happy stole one of the S class missions from the second floor, and that they plan to complete the mission so that the master would approve of them. Lucy at first didn't want to go due to breaking the rules and that the job is on the haunted island Galuna. Just as Happy and Natsu are leaving she notices a second reward on the request, one of the 12 ecliptic zodiac keys, so she decides to tag along.

The next day Mirajane notices the missing request tells the master about what happened. Just as everyone started to wonder what happened, Laxus says he saw a cat steal the request but did nothing to stop it. The guild quickly realize that it is Natsu and Happy who stole the request. Makarov tells Laxus to bring them back, but he bluntly refuses so Gray volunteers to bring them back.

Arrival on Galuna Island
Natsu, Happy, and Lucy arrive at Harejion hoping to find a boat to take them to Galuna, which Natsu doesn't want and proposes swimming there instead. They ask several sailors but all of them refuse when they reach the last sailor Gray shows up behind them to take them back to the guild, with the idea of expulsion and Erza's rage if they refused. Natsu still doesn't care and wants to continue with the mission and almost gets in a magic battle with Gray. They then reveal their magic which makes the sailor they just asked, to change his mind and take them to Galuna. Natsu knocks out Gray and takes him with them for fear of him going back and telling Erza.

Along the trip, Natsu gets sick and they learn of the curse on the island when the sailor Bobo, who is a former inhabitant of the island, shows them his transformed demonic left arm. When they can see the island, Bobo disappears and a giant tidal wave arrives to wash them away. In the morning the gang finds themselves washed up on the shores of Galuna with no way to leave. They decide to continue the quest with Gray deciding to help them. They arrive at the village who sent the request at night and after showing their Fairy Tail tattoos they gain entrance. The village chief tells everyone to take off their robes and everyone is shocked to see all the villagers having the same deformities as Bobo. The village chief explains about the curse and the purple moon. On nights when the purple moon comes out the villagers change into demon forms, at morning they return to their original forms, but some of them lose their minds so the villagers have no choice but to kill them. The village chiefs son bobo was one of them, and the gang think that the Bobo they saw yesterday was a ghost who couldn't rest in peace, which is why he disappeared. Realizing that the entire village is suffering the gang try to think of a way to help them, which the village chief says that the only choice is to destroy the moon.

The next morning Team Natsu decides to explore the island hoping to find the cause or an alternative besides blowing up the moon which they deem impossible. Along the way the are attacked by a giant mouse in maids clothing, after defeating it they spot a temple near by and decide to investigate. When inside Natsu accidentally destroys the floor and they discover a hidden cave, when they explore further they find a huge frozen demon, which gray instantly realizes is Deliora and starts to break down. They later hear foot steps and find a group of people who are not from the island and are planning something with Deilora and Moon Drip.

Reunion of Pupils
Gray explains that Deilora is an immortal demon that destroyed villages from the Northern Continent and was sealed in ice by his former mentor Ur. When Natsu suggest unfreezing the demon, Gray punches him and tells not to think of that. He starts to wonder what is going on since Deilora is trapped in an unmelatable ice, there would be no reason to move it to Galuna and even if they did they shouldn't have found its hiding location. He then proposes that they wait til nightfall to see what happens. Natsu falls asleep in an instant and Grays starts to remember his training days with Ur. While waiting Lucy decides to summon Lyra to pass the time. Lyra then sings a song that makes Gray cry. Later when night does come, purple moonlight shines down and hits Deliora. When they reach the top they see a ritual taking place, and Lyra explains that they are casting the spell Moon Drip which is a spell to undo any spell, including melting the unmeltable ice Deliora is trapped in and the cause of the villagers transformation is due to the Moon Drip.

Later the same group of people team Natsu met back in the cave, and Gray is shocked upon hearing the voice of the one in charge, who is none other than his sempai Lyon. He tries to stop him but their attack but they both use ice so their attacks cancel out. Lyon then orders the destruction of the village, Lucy and Happy head toward the village while Natsu gets trapped in one of Lyon's spell, luckily he was saved by Gray. Gray then asks why he is doing this, since he should know about the horror of Deliora. Lyon just says its for his dream which greatly angers Gray for betraying their teacher, but this make Lyon mad by reminding him that Ur died because of Gray. They then enter a ice battle but Lyon uses dynamic ice animals so they can move while Gray uses static inanimate objects. Gray is even more shocked to learn that Lyon still uses one hand to cast spells which their teacher taught them to use both hands since one handed spells are unbalanced. Gray is quickly overwhelmed and knocked unconcsious, when he wakes up he is found by Natsu who takes him back to the village and apologizes to Natsu for what he said about not being ready to take on an S class mission since he made the same mistake.

Natsu vs Yuka and Toby
Lucy arrives at the village to tell them about what is happening and that they may be able to save them without destroying the moon. She then summons Virgo and plans to make a pit fall trap to capture Team Lyon. instead she accidentally traps Natsu, and is surprised to see the enemy arriving by air instead using Angelica the mouse who can fly by spinning its tail. Team lyon plans to destroy the village with poison jelly which melts everything, but their plan fails when Natsu uses his Gleaming flame to push the jelly outwards.

They destroy Bobo's grave which makes Natsu upset so he challenges Yuka and Toby while Lucy challenges Sherry. At first Natsu has trouble fighting Yuka since his magic wave cause vibrations that can neutralize other spells. Realizing that spells don't reach him Natsu decides to use normal attacks despite the pain it causes him for entering Yuka's wave. He then ignites his elbow in flames which gives him the needed boost to punch and knock out Yuka. He then faces Toby and his paralyzing nails, he wins easily by tricking Toby into paralyzing himself with his own nails.