Bulma

Bulma is the reason there is a quest. She built the Dragon Radar as a teenager, worked out that seven scattered spheres would grant a wish, and set off across the country to find them so she could ask for a boyfriend. Then she ran into a child raised in the woods who owned one of the balls and had been using it as a keepsake. Everything else in the franchise follows from that meeting.

She is the heir to Capsule Corporation, the company whose pill-sized capsules unpack into houses, aircraft and motorcycles, and she keeps engineering long after the fights outgrow her. She reverse-engineers alien scouters, builds the ship that takes the cast to Namek, repairs technology nobody on Earth understands, and shouts at gods without lowering her voice. Later she marries Vegeta, which surprised everyone including, by his expression, Vegeta.

Toriyama named her after buruma, the gym shorts Japanese schoolgirls wore, and kept the theme in the family. Her son is Trunks, her daughter is Bra, her father is Doctor Brief. Once you notice that the Briefs are all underwear it is impossible to stop noticing.