Eragon (The Inheritance Cycle #1) (アラゲイジアの物語　ドラゴンライダー外伝　エラゴン1)

In Aagaesia, a fifteen-year-old boy of unknown lineage called Eragon finds a mysterious stone that weaves his life into an intricate tapestry of destiny, magic, and power, peopled with dragons, elves, and monsters