English: Bulma Briefs
Japanese: Buruma Briefs

Bulma is the first person Goku meets in Dragon Ball, and is also the first girl he ever encounters. She is quite a unique young woman: wealthy, very beautiful, amazingly intelligent (especially with things mechanical), daring, and adventurous. But she's definitely not without her faults... she's also obnoxious, selfish, bossy, and blindingly arrogant. So you can just imagine the kind of pair Bulma and Goku made on their early adventures.

Bulma is the character that sets the action into motion. She discovered a Dragon Ball in her home, and designed the Dragon Radar (a compass that detects the energies of the seven Balls) in order to help her find the others. That little invention, which she created as a teenager, gives testament to her mechanical skills. So, she leaves Capsule Corporation, the powerful technology conglomerate owned and operated by her father, and sets off on a globe-trotting adventure to find the seven Balls, and make a wish. And what is it that the girl who has everything wants most? At first, she couldn't decide whether she wanted a mountain of strawberries or the perfect boyfriend, but eventually she leans toward the boyfriend.

She encounters Goku in the woods of Mount Paozu, when she is following the energy signature of a nearby Dragon Ball. Goku leads her to the four-star ball, and joins her in an adventure that brings the pair face to face with a multitude of dangerous enemies, quirky allies, the Great Dragon, and even God (well, one of the many gods in the DB universe).

And for the record, she never did get to make that wish for the perfect boyfriend. But she did become smitten with fellow adventurer Yamucha, and they remained an item (on and off), throughout Dragon Ball and a significant chunk of DBZ.

By my estimation, Dragon Ball Z picks up about five years after Dragon Ball ends. And DBZ winds up being far more action-oriented than the first series, meaning Bulma takes a back seat and the fighters step forward. Still, she is a very significant character, who is constantly on hand to create some kind of useful gadget or just lend support to the team. Her most notable contributions include providing capsules, which are pellet-sized containers that can store any object by means of a shrinking process (which reduces volume as well as mass, allowing any typical human the ability to carry a house in their hand), the Dragon Radar, which is constantly used to locate the Dragon Balls, and her repair of an ancient Namek spaceship, allowing herself, Gohan, and Krillin to visit Namek and participate in the battle against Frieza.

During the Cell Saga, Bulma makes her most dramatic transformation: into a mother. While still hopelessly prideful and foolishly bold, we get to see her softer side, expressed through her interactions with her infant son, Trunks. We never get to see just how Bulma and Vegeta jumped from petty squabbling into bed, but it happens during the three years in which Vegeta lived at Capsule Corporation, utilizing the gravity chamber (created by Dr. Briefs) in an effort to reach the power level of a Super Saiyan. (If you're interested, there are literally hundreds of fanfics that fill the three-year gap where Trunks is conceived and born). At any rate, Bulma's attachment to Trunks is transparent, as she brings him with her everywhere she goes (unfortunately, including dangerous battle sites), and constantly plays with him. I, for one, was surprised Bulma had the capacity to love so much, but my hypothesis is she was always looking for someone to love outright (hence that "perfect boyfriend" wish, and her long-term but strained relationship with Yamucha), but had a great deal of difficulty finding one.

At some point (which exactly, I'm not sure) Bulma moves into an official role at Capsule Corporation, eventually becoming President after her father retires. And somewhere in the series (I'd wager between the Cell and Buu sagas), she and Vegeta become really exclusive. Whether they actually went through some kind of marriage ceremony is unclear, but Vegeta did refer to her as "my wife," so at least he considers her his mate. Unfortunately, romantic relationships are greatly underplayed on the show, but it gives enough hints that Bulma and Vegeta remain a strong couple. As time progressed, the pair becomes less hostile (to each other, and the other Z-Senshi). But while Bulma does mellow out a bit in her old age, she always remains the stylish, sassy, stubborn woman we met as a teenaged girl.