Although notoriously known as an alcoholic, Lusca was once a very highly respected and accomplished lawyer, who eventually turned to drinking after his life became a bit complicated. He was hired by Guys' family for the sole reason his fees were no longer expensive, but due to his alcoholism, he cared very little about Guys' case and did little to help the boy prove his innocence; however, after Guys was sent to prison, Lusca was paid a bit more money by the boy's family so he could visit him a total of 12 times in order to possibly gather new evidence. At first, Guys and Lusca do not get along at all, but through Evan, Guys discovers that Lusca was once a successful lawyer and that Evan and him used to work closely together before breaking off communication. Slowly, Lusca and Evan begin speaking again, and soon, Lusca starts taking Guys' case more seriously and drifts away from alcohol.
Lusca eventually gathers enough evidence (most notably witness testimonies from Guys' friends) for the court to grant a retrial, but their first attempt fails when Guys' friends claim on stand they cannot remember any details. Lusca, knowing the witnesses have been silenced by Guildias, loses the trial but continues to take the case seriously, working with Guys to gather even more evidence. When it becomes obvious the two are making progress, Guildias attempts to silence the lawyer by shooting him, but nonetheless, Lusca survives and does not lose his determination.
Depending on the scenario (in the game), Lusca may lose interest in the case all together (therefore prompting a bad ending to ensue), but it also possible for Guys and him to develop a romantic relationship two ways. The first is where, despite Lusca's greatest efforts, Guys fails to come up with evidence himself and ends up attempting an escape on New Year's Eve and is shot down by guards. While Lusca somehow manages to be with the boy as he dies, he later visits the boy's grave, subtlety confessing his love and promising to avenge his death by proving Bollanet, Guildias and Durer's guilt and freeing his friends in prison. In a not-so depressing ending (other scenario in the game and also the ending of the anime), Lusca and Guys will end up moving in together, become lovers and work together to prove the innocence of Evan, Vallewida and the rest of Guys' friends. However, no matter what scenario, so long as Guys proves his innocence, it is safe to assume Lusca regains his status as a successful lawyer.