*This is not related to Fairy Tail but is labeled as a parody if it.* Mex follows a 16-year-old boy named Rei Mitsuo, one of the millions of people possessed by dark magic known as Mex. It is unknown who or what Mex is but it is continuously spreading across the world. Rei is able to overcome the power of Mex and use Mex's power for good. But Mex will not let Rei live...

The story is set in a distant future in Koragami City where dueling has taken a new form called Future Summoning. The heroine is a 15-year-old girl named Yura Minako. Abandoning her old home, Yura now must compete for a chance to enter a grand dueling school. Then one day, as she prepares for a matchup, Yura encounters a familiar named Aru in her bag. What does this mean for Yura?

Daisuke Yashimira, a 15-year-old boy looking for fun in his dull life. One day, he hears on the news about the death of a girl named Minami Tsubasa. Then some days later, on the way to school, Daisuke finds a pendant laying on the ground with the name Minami. The odd thing about it was the date on the pendate which showed 8/14/13. Days later, he begins to see her wandering spirit.