Jō Yokosuka, nicknamed Joe, is a half-Japanese, half-European orphan who sports distinctive blonde hair, blue eyes, pale skin, and a mole under his left eye. This appearance contributed to a traumatic past marked by targeting from sexual predators.

Abandoned alongside his younger sister Meg by their parents, Joe assumed protective responsibility for her during their orphanage years. To secure better conditions for Meg, he endured sexual exploitation by the orphanage director, keeping this sacrifice hidden from her. This period concluded when he inflicted life-threatening injuries on a man attempting to rape him, resulting in a two-year sentence at Shōnan Special Reformatory for assault and illicit sexual conduct.

During incarceration, his quiet and reserved demeanor concealed underlying resilience. He demonstrated physical strength by overpowering the abusive Dr. Sasaki and exhibited fierce loyalty to his cellmates. Driven primarily by the need to reunite with Meg, he made a failed escape attempt facilitated by his friends. During this attempt, Meg publicly rejected him to shield him from further harm, deepening his emotional turmoil while solidifying his resolve to survive.

After release, he pursued a singing career to attract Meg's attention, leveraging his natural vocal talent. This path involved exploitation, including manipulation by the band Five-Lemons and a proposition from talent manager Yamaguchi demanding sexual favors for career advancement. Despite setbacks like violent intimidation by rivals, he achieved mainstream success. His performance at the Western Road venue culminated in his reunion with Meg, facilitated by his friends Mario, Turtle, and Cabbage.

In later life, he supported Meg's relationship with former cellmate Tadayoshi "Soldier" Tooyama, whom she eventually married. As an established performer, he honored a promise to deceased mentor Rokurouta Sakuragi by assisting the criminal Sakota, demonstrating his enduring allegiance to his reformatory bonds.