Bulma is the first person Goku meets on his journey as a kid and the stay together through the rest of the series. Bulma is a genius and is the person who invented the Dragon Radar. She Belongs to the "underwear family" you know Dr. Briefs, Bra, and Trunks. She is probably the most active non-fighters in the show. She did not marry Yamcha as everyone believed was going to happen, she married Vegeta and had 2 kids, Bra and Trunks.