Brad is a member of the floating colony. Living on the floating colony his entire life bred a feeling of animosity towards those who lived upon the ground (such as Vash and Wolfwood). He fell in love with another member of the floating society, Jessica, who unfortunately was head over heels for Vash.
In the first anime, Brad eventually assists Vash and Wolfwood in defeating those who invaded his home, however the floating colony still fell from the sky. Resulting in the sky people to be furious with Vash. Yet Brad redeems himself by taking the role of leadership, making a triumphant speech that the city was always doomed to fall to the ground and that Vash "at least had the courage to stand up to those who threatened them instead of hiding".
Brad dies an unfortunate and untimely death quickly after finishing his heroic speech by diving in front of gunfire meant to kill Vash (a gunfire coming from a Jessica's puppet, controled by Leonof the Puppet-Master). With his last dying breathe he talks about how much he has grown since Vash last saw him as a child before passing away in Vash' arms.
In Trigun Maximum, Brad is a punk who is always at the Doctor's side, the man responsible for Vash' combat equipment. During his childhood, Brad was very attached to Vash, but after what happened in July and the appearance of the crater on the fifth moon, he started to see Vash as a threat, blaming his clumsy way of wanting to solve problems, no longer trusting him. But as the story progresses, Brad gradually grows as a person and begins to help Vash in his fight against Knives.
In Trigun Stampede he is now older than Vash and is a companion of Luida and Rem, he is responsible for technical repairs on their ships. On his first meeting with Vash, Brad doesn't trust him either, but slowly starts to take care of him like a big brother. After Knives ripped off Vash' left arm, Brad gave him a prosthesis using the lost technology. Time has passed, Brad has aged along with Luida, but he is always ready to help Vash when he needs it.
