Natsu and Happy discover an egg that falls from the sky and hatches into a small, fire-breathing creature, which Natsu names Kemo-Kemo. Meanwhile, the Magic Council initiates a member exchange program between the guilds that participated in the Grand Magic Games; Natsu volunteers as one of the exchange members, interested in asking about Kemo-Kemo's origins across Fiore. As he and his friends visit the other guilds and cause problems for their respective members, they notice Kemo-Kemo growing larger and more powerful. When Fairy Tail visits Saber Tooth, the Council cancels the exchange program and requests the two guilds to investigate a mysterious island that has risen from the sea.