Son Hiro is the second son of Gohan and Videl, and is the same age as Pan. As of the end of DBGT, he is fifteen. He tends to unintentionally annoy Pan.
During the end of DBZ, Hiro has his grandpa's first orange gi, which has numerous cuts on it, something Hiro admires, aiming to make his gi just like that. In DBGT, he wears a gi similar to Goku's during GT, but with dark blue instead of sky blue.
Unlike his sister, Hiro has kept his tail, saying its useful in situations, like during DBGT when Android 17 attempts to draw him into the Accel Ball he was charging. He wrapped it around a tree trunk and stayed there, while preparing a Kamehameha. Though the tail has also caused some casulaties, such as at the World Tournament, when he was up against Buu, the Moon came early, forcing him into a Great Ape form. Gohan blew up the Moon, which turned out to be a trick by the King Pilaf, who wanted Hiro to squash Goku.
Hiro's personality is almost the same as his Grandpa's, caring, and always up to a good fight. However, during a major fight, he is serious and quick to anger if something happens to his family, like when Luud absorbed Pan, he used a 20x Kaio-ken Kamehameha to blast him.
He can also read people's emotions by staring into their eyes, something Goku failed to achieve.
Kamehameha - Hiro's signature move. It was taught to him by his father, and has demonstrated a knack for creating new techniques with it.
Super Kamehameha - A more powerful version of the Kamehameha. It is powerful enough to give an opponent a serious injury. It can also power-up physical attacks.
Dragon Fist - Hiro's other signature move. His version is where he launches himself towards the enemy with a Super Kamehameha and thrusts his right fist forwards, forming a Golden Great Ape shape, similar to the Shenron of Dragon Fist.
Kaio-Ken Kamehameha-A kamehameha power up by Kaio- Ken