For a time, Boswell was married to Sean's mother and the three of them lived together. When Sean was three, he divorced his wife. He was later relocated from the United States and stationed in Tokyo, Japan. Since living in Tokyo, Boswell has enjoyed the company of Tokyo prostitutes.
The Fast and the Furious: Tokyo Drift
Sean's father agreed to take his son on after his mother made a deal to keep him out of prison with the local police. When Sean arrived at his father's house, Boswell warned Sean that stay away from cars and street races or he would send him back to the United States to prison.
The day after Sean's arrival, he participated in a street race. Boswell attempted to scare his son with jail time, but Sean called his bluff and told him to call the police. Instead, Boswell gives Sean another chance to do right by mother's deal. Sean, however, continued to race and eventually left his father's home to live in Han Seoul-Oh's garage.
Following Han's death in a car accident, Sean went to his father for help. Boswell defended Sean and his friend, Neela, from Takashi, the nephew of a Yakuza member. Neela gave herself to Takashi to avoid any bloodshed on her account. Following her departure, Boswell told Sean he'd put him on a plane to send him back to America, but Sean tells his father that he intended to stay and clean up his messes, not run from them. Boswell had a change of heart and reluctantly agreed to let Sean stay and decided to let Sean race, using his 1967 Ford Mustang Fastback.