Episode 4 of "Weak Hero Class 2" resumes right where the tension thickened, with Seung-je enticing Si-eun to accompany him to an unexpected destination: a bowling alley housing Baek-jin's office. Without so much as a glance up, Baek-jin curtly instructs Si-eun to await his attention. However, Si-eun's visit is less about dialogue and more about delivering an ultimatum. He sternly warns Baek-jin to keep his minions at bay from Su-ho, threatening dire consequences if they don't comply. Amidst this gravity, Si-eun Lightheartedly assists Baek-jin with a math problem that had him stumped, then turns to depart with an air of finality. Baek-jin, though not contesting, pleads with Si-eun to uphold his end of the bargain and steer clear of Hu-min.
Later that evening, Baek-jin's minions orchestrate a mischief aimed at Hu-min's father. Armed with fake IDs, they procure alcohol at the elder Hu-min's restaurant and promptly call the police, falsely accusing him of selling to minors. Panicked phone calls ensue, with a neighbor urging Hu-min to rush to the restaurant to quell his father's distress.
The following day, Si-eun informs Hu-min of his desire to distance himself from their circle, preferring solitude over the entangling web of conflict between Hu-min and Baek-jin. As school concludes, Si-eun makes an early exit for cram school, while Hu-min fibs about a date to slip away and confront Baek-jin at a given address.
Concurrently, Seung-je and his Union gang are dispatched on a mission to track down Hyun-tak, Jun-tae, and Si-eun. Si-eun briefly encounters a contingent from Ganghak High, but they let him be, respecting Baek-jin's orders to leave him unmolested. Elsewhere, Jun-tae and Hyun-tak cross paths with Seung-je's Ganghak High gang. Hyun-tak sacrifices his own safety to give Jun-tae a head start, as two members chase him while Seung-je and another confront Hyun-tak. Jun-tae, managing to evade his pursuers momentarily, calls Si-eun for help despite urging him to stay away. Undeterred by Jun-tae's plea, Si-eun rushes back to his aid, driven by a sense of duty amidst the escalating chaos.
Meanwhile, Hu-min storms into the bowling alley, determination etched across his face. A contingent of Union members attempts to intercept him downstairs, but his fierce demeanor quickly cowers them into submission, reluctantly divulging the directions to Baek-jin's office. Inside, Baek-jin persists in his effort to recruit Hu-min, outlining an ambitious scheme to transform the Union into a lucrative venture upon graduation.
Hu-min scoffs, labeling Baek-jin an idiot and asserting his unwavering refusal to align with his faction. Baek-jin, undeterred, mocks Hu-min's foolhardy insolence, revealing the true nature of their meeting – a calculated maneuver to distract Hu-min while the gang targeted Hyun-tak. Tempers flare, and Hu-min itches to confront Baek-jin physically, yet he restrains himself, opting for a different course of action.
As he exits, another cohort of Union thugs tries to bar his path, but Hu-min dispatches them with ease, displaying a prowess that leaves them in awe. Baek-jin, recognizing the futility of further confrontation, steps aside and allows Hu-min to depart. However, Hu-min pauses, clarifying the situation with a note of superiority. It was he, Hu-min, who mercifully spared the lives of the Union members, not Baek-jin granting him mercy. The air is thick with unresolved tension as Hu-min leaves, leaving Baek-jin to ponder the ramifications of their encounter.
Hu-min desperately strives to dash to Hyun-tak's aid, his heart pounding with urgency. Meanwhile, Seung-je revels in his brutal dominance over Hyun-tak, each punch landing with a sickening thud, while his fellow gang members eagerly broadcast the grueling confrontation live. Jun-tae stands helplessly on the sidelines, his eyes wide with horror and impotence.
Si-eun, fortuitously overhearing a conversation among some boys he encounters, learns of the fight's location. Without a moment to lose, he bolts towards the rooftop, arriving just as Seung-je prepares to capture a triumphant snapshot of the battered Hyun-tak and the powerless Jun-tae. Without hesitation, Si-eun lunges at Seung-je, igniting a fierce battle.
Though Seung-je possesses a formidable punching prowess, surpassing Si-eun's, Si-eun counters with relentless ferocity. His singular objective is to neutralize Seung-je, and he achieves this by employing Seung-je's glasses as a weapon, shattering them and using the jagged frame to pierce Seung-je's foot.
The fray persists, with Seung-je seeming to thrill in the combat, his excitement evident despite the futility of his efforts to fell Si-eun. Each time he strikes, Si-eun rises anew, his gaze unwavering and devoid of fear. Seung-je, determined to deliver a finishing blow, prepares his strike, but Si-eun, anticipating his intent, launches his own attack first. Both men tumble to the ground, utterly drained.
In the distance, the wail of sirens pierces the air. At this crucial juncture, Hu-min arrives on the rooftop, his breaths coming in ragged gasps. He rushes to Si-eun's side, who, in his dazed state, mistakes him for Su-ho. With a voice tinged with regret, Si-eun confesses to Su-ho that he has once again found himself in a fight and offers a heartfelt apology, before succumbing to unconsciousness.
