Goku's first child. Born when Goku fought Evil Piccolo Jr., Gohan is 4 years old at the time Raditz ushers in the Saiyan invasion of earth.

Chichi wanted to name him "Einstein" or "Archimedes." Accordingly, Chichi, as a education-minded mother, pushes text books on to Gohan from an early age. Gohan decides he wants to become a scientist when he grows up.

However, Gohan's fighting career seems inevitable; Piccolo becomes Gohan's first teacher and mentor when he drags Gohan out to train with him, in order to whip Gohan into shape and prepare for the impending arrival of Nappa and Vegeta.

After Vegeta is defeated by Goku (he has been revived by the Dragon Balls), Gohan decides to join Krillin and Bulma on their expedition to find the Planet Namek Dragon Balls so they can save those killed by the Saiyan invasion. There, he fights the Ginyu Special Combat Team and Frieza.

Back on earth, he fights evil Android #19 along with the other warriors. After Goku recovers from his heart ailment, Gohan trains with his father to ward off the evil Cell, who has decided to wipe out the planet unless someone comes to stop him. Goku, realizing he can't beat Cell, banks his hopes on his son, who has the ability to power up enormously with anger. The fight with Cell, one of the more dramatic scenes of the series, is a test of Gohan's strength, will, and morals. Gohan, despite all his combat experience, is a pacifist deep down. After all, he wants to be a scientist when he grows up. During the fight with final stage Cell, he becomes Supersaiyajin 2.

Later, when he is 16, Gohan begins to attend Orange Star High School in Satan City, leading a dual life of ordinary student and crime fighter "Great Saiyaman." At this juncture, he enters his first tournament, However, he leaves in the middle of the tournament in order to stop the evil machinations of Badi-di, a sorcerer who releases a monster named Buu. Gohan battles Dabura and evil Buu.