Hiro is a white-skinned, red-cheeked little Human is the son of Tiana Shinhan and Joey (owned by someone else), the grandson of Tien Shinhan, Chiaotzu, and Yamcha, the nephew of Cheese, and the twin brother of Chiro.
Tien - Maternal grandfather. Even though he never met him until his own death, he respected him very much.
Chiaotzu - Like with Tien, even though he didn't know him until his own death, he respected very much.
Yamcha - Paternal grandfather, even though he never met him until his own death, he respected him very much.
Tiana - Mother. She's the one who carried him and Chiro for nine months and given birth to them, she watched over them and protected them from the dangers that earth had to throw at them. She couldn't save them from Tao, which she promised to kill for her loved one's deaths.
Joey - Father. Joey raised him since the day he was born and along with Chiro, both of them were murdered by Tao.
Chiro - Hiro's twin brother who, along with their father, was murdered by Tao.
Along with Hiro and their father, Joey, he was murdered by Tao in front of Tiana and leaving the their bodies there.