Episode 1 of "Half Man" commences at Niall Kennedy's wedding, where a palpable tension looms between him and his brother, Ruben Pallister, in a dimly lit barn. Despite the celebratory aura surrounding Niall's nuptials, Ruben's presence is not a sign of well-wishes but a harbinger of conflict. A brutal punch from Ruben leaves Niall reeling, almost unconscious, as the brothers' strife takes us back to their tumultuous teenage years.
In a flashback, Niall is the target of relentless bullying at school, with Gus and his cronies hurling homophobic slurs and taunts. Gus even steals Niall's cherished Indiana Jones collectible cards, rubbing one of them on his genitals before forcing it into Niall's mouth as Mr. Jenkins enters the room, silencing the chaos. Jenkins emphasizes the importance of students preparing for upcoming exams, only to announce that Ruben will be transferring from Polmont Young Offenders Institute to their school.
Niall's anxiety spikes at the mention of Ruben, prompting him to call his mother immediately. Lori abruptly ends the call, insisting they discuss Ruben's move when she picks him up from school. On the drive home, Lori reveals that Ruben will indeed be living with them and sharing Niall's bedroom. She apologizes for not informing him earlier and urges Niall to be happy for Maura, Ruben's mother, who has extended her stay beyond the initial six months.
Niall's excitement is dampened by Maura's overstay and the fact that her son will now be a permanent resident. Meanwhile, Ruben has already settled in, transforming the room to suit his preferences. Their initial interactions reveal a history of past encounters from their youth. Ruben tidies up the room and extends a hand of collaboration to Niall.
The next day at school, Ruben's absence was conspicuous, and Niall discovered his notebook adorned with a gruesome image and the words "my mother is a 'dyke'" inscribed across his notes. The class's amusement drew Mr. Jenkins's attention, who insisted on inspecting the notebook. Jenkins asked him to name the culprit, prompting Niall to erupt in a fit of anger and lash out at him. This outburst led to his being escorted to the office, and Lori was summoned to the school. Jenkins reprimanded her, implying that there might be something at home that was causing the usually studious and calm Niall to act out.
At home, Niall witnessed Maura comforting Lori with love. Later that night, Ruben's estranged father arrived at the house, drunk and shouting a barrage of profanities at Maura, stating that his son should choose to stay with him rather than his lesbian mother. Niall wanted to call his mother, but Ruben prevented him by choking him and holding him tightly until they both fell asleep in each other's arms.
The following morning, Lori and Maura tried to bring up the commotion, but Niall shut them down, saying they were both asleep and did not hear anything. Ruben and Niall walked to school together and encountered Gus. Ruben demanded to know if Gus bothered him at school. When Gus admitted it, Ruben pulled out a knife, telling him to run to school so he wouldn't become a witness to whatever he did next. Later, Ruben showed up for class, but Gus did not.
At home, Maura and Lori asked Niall to persuade Ruben to take the prelims. Maura tried to make him agree by acting cute and tickling him, but it backfired when he knocked her away.
Lori sat him down to make him understand that Maura had worked tirelessly to transfer Ruben to Dilkennie. She added that Ruben was on probation and if he failed to take the prelims, he would be dismissed from the school. Niall went to the room to try to talk to Ruben, only to find him dancing all by himself. Ruben got aggressive with him, demanding that he never tell anyone that he danced. Niall tried to pass on Lori’s and Maura’s request, but he was immediately shut down. Later that night, Ruben and Niall talked about his father, who had passed away. He worked at a bar and wanted to be a writer, which is why Niall also tries to write by keeping a diary. Niall asked about Gus, and Ruben updated that he hadn’t done anything serious. He wanted to use the knife but didn’t, so that he could live.
The next day at school, Gus showed up with his face all bruised and ordered his minions to stop messing with Niall. Ruben showed up for the prelims, though late. When Jenkins announced ten minutes to go, Ruben wanted more time since he was late. He flipped the desk and walked out when Jenkins failed to oblige. Jenkins and the other invigilators followed Ruben out, allowing Niall to pick up his paper and mark the correct answers. At home, Maura was happy that Ruben passed the Prelims and thanked Niall for being a positive influence on him.
Later that night, Niall was woken up by Ruben sneaking Mona through the window. Niall was caught red-handed trying to take a peek at their sexual interactions, and Mona got on top of him. At first, Mona’s advances didn’t work on him, so Ruben tagged along, helping him climax. It turned out that Ruben had arranged for Mona to help Niall lose his virginity as a thank-you gift for helping him pass the prelims. Ruben also gave him a pair of boxing gloves, saying that he intended to train him so he could take care of himself when he was no longer around.
The flashback ended with Ruben and Niall walking to school together, catching the attention of the students and even Jenkins. In the present day, Ruben physically assaulted Niall until he bled and then helped him calm down. At the end of the episode, Ruben helped him breathe easily and then proceeded to seemingly choke him.
