Episode 4 of "My Dearest Nemesis" kicks off with a poignant flashback to Ju-yeon being chauffeured by his parents to his beloved anime convention. Their journey is abruptly shattered when a truck careers down the wrong lane, claiming the lives of his doting parents. In the aftermath, his grandmother harshly declares that he has no right to grieve, blaming him for their untimely demise. One fateful day, catching her in tears, Ju-yeon is consumed by self-recrimination, convinced he bears responsibility for their loss. Determined to atone, he endeavors to win her favor, though she remains an enigmatic figure, resistant to his efforts.
In the present, Ju-yeon finds himself in a delicate situation, attempting to pass off his cherished otaku sanctuary as belonging to a nephew to Su-jeong. Amused by his transparent lie, she confesses her awareness but dismisses it, cherishing the deeper connection they've forged. A sudden stumble by Su-jeong leads to an awkward moment as Ju-yeon catches her, leaving both flustered. Amidst laughter, he reluctantly allows her to mend the plug while she confides in him about her dress dilemma, to which he playfully responds by claiming it as a gift meant just for her.
Interrupted by a call informing her of her father's ankle fracture, Ju-yeon insists on driving her to the hospital. His generosity extends further as he handles the medical expenses and secures a VIP room for Mr. Baek. As he departs, he notices Su-jeong's tearful contemplation of her late mother, yet she still manages to send him a heartfelt text of thanks. Her brother, Su-bin, arrives, revealing his intensive preparation for the government exams and his characteristic pestering nature, questioning if Su-jeong is romancing her boss. Grossed out by the notion and mindful of Ju-yeon's youthful appearance, she finds her brother's joke about her unattractiveness to peers amusing yet painful.
Undeterred, Ju-yeon goes above and beyond, bringing Mr. Baek thoughtful gifts, including the very stuffed toy Su-jeong once admired—a replica of one his parents had gifted him. He also discovers her toolkit left behind at his place, hinting at their burgeoning bond. At the office, a surprise visitor, an elderly woman, claims her limited-edition toy, leaving the team astounded by this rare treasure.
We continue to witness heartwarming moments unfold in the Baek family, as Su-bin displays his filial piety by insisting on caring for his father, while also expressing concern for Su-jeong's well-being, urging her not to exhaust herself and encouraging him to concentrate on his studies. Equipped with her toolbox, Su-jeong determines to make amends for the previous hit-and-run incident, yet Ju-yeon declines her gesture, burdened by guilt over selling the dress. Ironically, her car conks out at this very moment, prompting Ju-yeon to insist on fixing it to prevent any potential mishaps. As they await the repairs, their conversation drifts to Ju-yeon's late mother, and he suggests finding solace in activities like video games. She confides that she used to indulge but fell prey to a scam. Given the extended time needed for repairs, Ju-yeon generously lends her a sleek car, which she reluctantly accepts.
Elsewhere, Ju-yeon is en route to an important meeting when a child accidentally drops his tablet. He gracefully declines any compensation, viewing it as a mere accident. However, the sole remaining copy of his report resides on his work computer. In a desperate bid to convey the password to Su-jeong discreetly, he whispers it, but she fails to catch it. Frustrated, he blurts out "Orewa akuma da," inadvertently revealing the catchphrase from Dragon Ball. Once he retrieves the report, the meeting proceeds smoothly, even earning him a commendation from his usually stoic grandmother.
That evening, Shin-won, filled with thoughts of Ha-jin, takes a friend to Sulo, which is thriving. Unable to shake off Ha-jin from his mind, he asks her out, only to be met with a polite refusal. Amused by his astonishment, she chuckles, unaware that he has never encountered rejection before.
Su-jeong finds herself repeatedly amused by Ju-yeon's flustered reaction after revealing his password. She chuckles to herself, earning a teasing remark from her brother who labels her weird. At work, she offers Ju-yeon a chocolate milk, which he initially hesitates to accept but eventually succumbs. Her smile widens as he agrees that it's comforting to know someone shares his secret, reminiscing about a similar conversation she once had with Black Dragon.
That fateful evening, Ju-yeon happens upon Ha-jin quite by chance. A nostalgic glimpse into 2014 reveals him earnestly apologizing to her for his abrupt disappearance, as he prepares to embark on a journey to the United States for his studies, hinting at an inevitable separation. Yet, she persuades him to occasionally engage in team battles, weaving a thread of continuity between them.
In the present, he arranges for them to converse over the phone while seated at separate tables, shrouding their encounter in a veil of secrecy. Bewildered by his enigmatic demeanor, she seeks an explanation, but he merely cautions her against acknowledging him publicly before stealthily departing.
Just then, Su-jeong enters the scene, unbeknownst to Ha-jin that she had overlooked Black Dragon's presence. Their conversation drifts to Mr. Baek, and Su-jeong expresses her astonishment at how her brother and the director have been instrumental in her recent endeavors. Ha-jin's curiosity piques, wondering if Su-jeong harbors feelings for her director.
Meanwhile, she posts a snapshot of her latest culinary creation, which promptly garners Shin-won's approval. A peek into his personal life unveils his parents' romance, starkly contrasting his own love life. He ponders over his shortcomings, amidst his father's playful teasing about his lack of seriousness.
Back at the workplace, tensions escalate as Su-jeong reprimands Ju-yeon for selecting underperforming brands for the revamp. While others blindly accept his privileged decisions, she stands out as the sole individual who dares to question him. Unbeknownst to her, this was all part of a test, and she emerges victorious in her skepticism.
Su-jeong feels betrayed by the Black Dragon's deceptive antics, but Ju-yeon insists on lifting her spirits in gratitude for the chocolate milk. Touched by his gesture, she realizes it's not a promotion but an invitation to an arcade—a surprising turn of events.
The atmosphere is electric as they engage in a fierce competition, their rivalry igniting with each game. When Ha-jin calls for dinner, she seizes the opportunity to play matchmaker, revealing her whereabouts to him. Inviting them both, the evening takes an unexpected twist when Su-jeong's shoelace comes undone mid-walk. In a classic K-drama moment, Ju-yeon bends down to tie it, their eyes locking in a charged gaze.
As My Dearest Nemesis Episode 4 draws to a close, Ha-jin's sudden call to Su-jeong shatters the serene ambiance, informing her that Black Dragon has arrived. Su-jeong's face registers shock, while Ju-yeon stands puzzled, wondering about the unfolding drama.
