"Forever doesn't exist." People would often say that to Lucy Heartfilia. She never did believe them. But she did have her doubts when she transferred into Magnolia High in the middle of the school year, due to several... issues. 'It's a simple logic', she often told herself, 'new students would either be approached, or left alone.' Not that she minded being alone. But that logic never did apply to Natsu Dragneel--who spoke to her the moment she stepped one foot into the classroom. She made friends with his friends, and they made even more friends together. And with those friends, they made memories. And Lucy had never been happier. And no matter how cliché and cheesy it sounded, they made a promise. A promise to be friends forever. Because... When you've found something genuine, you would never let it go, right? Lucy thought that too. But then...

Fairy Tail had just about returned back to its outgoing state, months after the Grand Magic Games incident. Spring had just ended and the air was getting warmer, preparing for summer. But when a strange mark had appeared on Lucy's arm, she knew things weren't just right yet. Discovering about the 'no-jobs' ban for all the guilds in Fiore because of a strange sickness that leaves recovered wizards without their magic, Team Natsu decides to take on a special request from The Council to investigate. After being ambushed by a mysterious man in Hargeon, the team returned to Fairy Tail, and Lucy realizes her key to Aquarius had been stolen. Not only that, but the strange sickness had spread to Magnolia, and they find a young girl bearing Aquarius's key, who is unable to recall anything. The sickness is spreading faster, and they are running out of time, so they took the only option they had; track down the strange man who had ambushed them in Hargeon.