The story begins with a young boy named Gon, who aspires to be a hunter just like his father Ging. Ging leaves his son in the care of Mito, Gon's aunt, and has not been seen since. Gon catches the local monster fish, "Lord of the Lake", in order to prove his ability to take the exam. Although Mito is reluctant to let Gon leave his home, she relents after he is determined to understand the reason his father left him and his interest of being a hunter.

Gon decides to send a letter to his aunt Mito in order to inform her about the events that had happened during his journey. He started to narrate the story on the events starting from the preliminary Hunter exam to the point when he met Leorio, Kurapika, Killua and the other examinees.

A letter from Gon arrives at Whale Island for Mito... (A recap of everything that has happened.)

After learning Nen and becoming a true Hunter, Gon returns to Whale Island with Killua. When he arrives, Mito has a box for him. She was told by Ging to give this box to Gon once he became a Hunter. However, it appears that the box cannot be opened.

Gon and Killua have begun to listen to the cassette tape left behind by Ging in anticipation of Gon becoming a Hunter.