Named after his adoptive grandfather, Gohan is Goku and Chi-Chi's eldest son. He is idealistic, good and pure like his father. Gohan reveals his tremendous fighting potential when the earth is threatened. His heritage as part Saiyan an part human, makes him stronger than if he were of one race alone.
With Goku's departure to the next dimension and the eminent arrival of Saiyans stronger than Raditz, Gohan is the key to survival of Earth. Thus, Piccolo, a former enemy of his father, joins forces with the good guys and trains Gohan for the upcoming battle. Over time, Gohan becomes friends with Piccolo, looks up to Piccolo and even wears similar clothing.
Although initially a wimp, Gohan's training in the wilderness and subsequent fighting make him both brave and loyal. Following the fight on Earth, Gohan is determined to go with Bulma and Krillin to Namek to collect the seven Namekian Dragon Balls and help out his friends on Earth - especially since he feels he let them down during the fight on Earth.
Gohan is the key to the good guys success on Namek, risking his own life to save Dende, collecting Dragon Balls, traveling to see Guru who awakens a power sleeping within him, battling the Ginyu Force, etc. He will be the first to reach Super Saiyan II stage.