Natsu's name means summer in japanese, probably relating to his magic, fire dragon slaying magic. In the first episode, he meets Lucy Heartfilia, a celestial mage. He was found in the forest by Igneel, who taught him magic. He joined Fairy Tail after Igneel suddenly left on July 7, year 777.
Natsu was taken in by Igneel, and was taught magic by him. Natsu died when he was younger, but Zeref, his older brother resurrected him. As Zeref and Natsu's relationship started breaking apart, Zeref told Natsu he was actually the book of E.N.D. and proved it by piercing the book, which caused Natsu to feel pain where the book was struck. Gray Fullbuster, wants revenge on E.N.D. for Deliora was a demon from the book and Deliora killed his family and his mentor, Ur.