Luke is the fourth member of Ceres' Bison gang, joining after Riki, Guy, and Sid. He recruited Norris into the group. Known for his blunt and straightforward personality, Luke speaks his mind without hesitation, frequently using sarcasm and calling out others on perceived shortcomings. He gained a reputation among peers as a "virgin stalker" due to his tendency to pursue sexual relationships solely to be someone's first partner, ending encounters abruptly to avoid emotional attachment; this reputation's accuracy is suggested as potentially exaggerated by jealous observers.

Luke openly acknowledges a long-standing physical attraction to Riki, the gang's leader, which he historically channeled into loyalty and respect for Riki's leadership. This dynamic shifted dramatically when Riki returned to Ceres after a three-year absence as Iason Mink's pet. Luke perceived Riki as weakened and broken, leading to a significant loss of respect. Despite this diminished regard, Luke's sexual desire for Riki intensified, and he felt emboldened to act on these impulses due to Riki's subdued demeanor.

Luke became the most vocal critic of Riki within Bison, pushing for a confrontation. Failing to gain support from Sid or Norris for a physical advance, he challenged Riki to a game of Gigolo with Riki's body as the stake. Riki accepted. Luke won one round, resulting in a passionate kiss, but the game was interrupted before completion. Luke's aggressive pursuit subsided after witnessing Riki reassert his authority by leading Bison against the rival Jeeks gang, which restored some of Luke's respect and caused him to regain control over his urges.

Later, Luke actively assisted Guy in tracking Riki after his disappearance from Ceres, joining Guy on dangerous trips to Neal Darts and Apatia. Upon locating Riki in Apatia, Luke confronted him with sarcasm, accusing him of abandoning Bison for luxury with a wealthy patron. This confrontation ended abruptly when Iason Mink intervened and publicly humiliated Riki, leaving Luke speechless.

Luke also had casual sexual involvement with Kirie, a younger Bison member, partly due to Kirie's resemblance to Riki. Luke recognized Kirie's brattiness and treated him with sarcasm. After Kirie betrayed Bison and left Ceres to seek fortune elsewhere, Luke displayed open antipathy towards him.