Episode 10 of "My Dearest Nemesis" kicks off with Su-jeong and Ju-yeon basking in a whirlwind of smiles and affection, their bond seemingly unbreakable as he reluctantly bids her farewell. The night takes a cozy turn as they drift into a peaceful slumber, intertwined in their dreams. However, the morning sun brings with it an unexpected hurdle; Su-jeong's father catches her attempting to slip back into their abode. In a tender revelation, he confesses his sole wish for her—that she finds happiness wherever it may lead.
Their brief moment of bliss is abruptly shattered when Ju-yeon receives his termination notice. The Chairwoman, armed with photographs of Ju-yeon escorting Su-jeong home, lambasts Kwon, unaware that the secretary had been shielding their burgeoning romance by denying any involvement. Touched by Ju-yeon's newfound love, Kwon decides to resign, comforted by the knowledge that he has Su-jeong standing by him. Desperate for redemption, Ju-yeon pleas to his grandmother at headquarters, but her harsh words branding him as flawed leave him realizing he'll never measure up to her stringent standards. On the brink of confronting the Chairwoman, Su-jeong notices Ju-yeon's defeated departure, his spirits crushed. As he weeps inconsolably in his car, Su-jeong waits patiently for him, resolute in her support.
A silver lining emerges: they no longer need to conceal their passions or personal life, freely planning dates and Su-jeong eagerly agreeing to attend one of Ju-yeon's concerts. Shin-won, initially worried, finds solace knowing Ju-yeon is with Su-jeong. His mother, sneaking up on him, beams with joy upon discovering his blossoming romance. In a surprising twist, Shin-won reveals his heartfelt desire to spend his life with Ha-jin.
Ju-yeon meets with Kwon, who unmasks her knowledge of all his secrets, revealing she kept quiet out of a desire for his happiness. They part on amicable terms, with Ju-yeon expressing gratitude for her unwavering support. Jobless now, he opts to wait for Su-jeong at her home, where he unexpectedly encounters Su-bin. They share a meal marked by playful sibling rivalry and heartfelt discussions about work, Su-jeong, and a revelation that Su-bin has only shed tears twice—once for Black Dragon and once for Ju-yeon.
Determined to redeem himself, Ju-yeon resolves to lend a hand to the Baek family while they are at work. He eagerly tags along, tackling various chores with a sprightly demeanor that brings a smile to Mr. Baek's face. As conversations unfold, a note of melancholy creeps into Mr. Baek's voice, expressing his helplessness in providing more for his daughter. Ju-yeon, sensing his plight, solemnly vows never to bring her harm.
Elsewhere, the Chairwoman is faced with the question of her successor and appoints Park Ji-cheol as the new director, issuing a directive for Su-jeong's discreet dismissal. Returning home to find Ju-yeon whipping up a feast for everyone, the Baeks are pleasantly surprised by his culinary prowess, leading the menfolk to warmly adopt him into their fold. A playful squabble erupts over who gets to share a bed with Ju-yeon, ultimately resulting in the three men camping out in the hallway.
Su-jeong finds this scene endearing and sends Ju-yeon a text, inviting him to join her in the attic. With a touch of braggadocio, he regales her with tales of his hardware accomplishments, eliciting chuckles from her. They spend a cozy night lost in the pages of manga together. As he bids her farewell the next morning, Ju-yeon's heart swells with gratitude for her loving family and he solemnly promises never to make her shed a tear again. Her smile in response is radiant.
However, life throws a curveball when Su-jeong learns of her transfer to the technical department. She apologizes to her loved ones, bravely confessing her relationship with Ju-yeon. Taking the change in stride, she embraces her new role as a technician. Her female superior, sensing injustice, fumes on Su-jeong's behalf, ultimately confessing that her resentment stemmed solely from Su-jeong's unparalleled work ethic and unwavering dedication.
Shin-won and Ha-jin are deeply concerned about the young couple's plight, yet their own lives are far from drama-free. Mrs. Seo storms in with Ha-jin's ex, who harbors hopes of rekindling their past romance. Ha-jin, exasperated, finally unburdens herself to her mother, revealing the ex's betrayal. Mrs. Seo, heartbroken and enraged, attempts to strike the unfaithful lover but is caught off guard. Shin-won swiftly intervenes, escorting the ex out with authority.
At the hospital, the Seos offer heartfelt apologies for mistakenly blaming Ha-jin for her divorce. Ha-jin confesses her blossoming relationship with Shin-won, much to Mrs. Seo's astonishment, who promptly begins envisioning their wedding. Ha-jin, however, looks troubled, fearing she might have inadvertently pushed Shin-won away.
Meanwhile, Ju-yeon's suspicions peak when Su-jeong's evasiveness during their phone call prompts him to probe further. Matters escalate when the Chairwoman confronts Su-jeong, puzzled by her refusal to leave. Su-jeong insists she stays to pave the way for Ju-yeon's return, extolling his unparalleled dedication to earning the Chairwoman's approval. Her monologue ends abruptly as she exits, only to be confronted by an increasingly skeptical Ju-yeon, who discovers her in a new uniform. He is distressed by her tolerance towards the Chairwoman for his sake, but she stands firm, asserting it's a choice she's made for herself and her love for him.
Later that evening, Shin-won arrives at Mrs. Seo's laden with gifts and rambles about enhancing Sulo's security with CCTVs. Ha-jin feels uneasy about his overbearing concern and urges him to stop. He refuses, desiring a partnership where they share both joys and sorrows. She, however, declines and storms off.
The My Dearest Nemesis Episode 10 concludes with a grand business agreement ceremony for the renewal project. At the eleventh hour, the Chairwoman is summoned away, creating an unexpected opening for Ju-yeon, who steps forward, reintroducing himself as the director.
