DNA Lover, episode 9, kicks off with Mi-eun poring over photographs of her and Yeon-u, her mind swirling with questions about the timeline of their bond and the budding sentiments she harbors for him. Meanwhile, oblivious to the complexities of Mi-eun's feelings, Yeon-u merrily orchestrates a date with So-jin, reveling in the sweetness of their burgeoning relationship.
Concurrently, Gang-hun's heartaches surface as he acknowledges his unspoken affection for So-jin, lamenting the missed opportunities that may have led him to her side.
On So-jin's discharge day, a heartwarming gesture unfolds as Yeon-u presents her with a pair of shoes, while she reciprocates with a couple's bracelet set. Though unaccustomed to such sentimental displays, Yeon-u feigns delight, assuring So-jin he'll cherish it always, a lie that eases her heart. Gang-hun, arriving to offer his support, masks his inner turmoil with a veneer of nonchalance, striving to be genuinely happy for So-jin's joy.
Elsewhere, Jung-tam bravely steps up to participate in a gym photoshoot campaign alongside Sung-mi. She agrees enthusiastically, vowing to guide him towards fitness perfection by the shoot's deadline. However, the relentless grind of workouts soon takes a toll on Jung-tam, who confides in Yeon-u. Wise counsel ensues, urging Jung-tam to be transparent with Sung-mi, believing that true affection would understand and accommodate his limitations.
As days blend into a tapestry of romance, So-jin and Yeon-u's emotions deepen, their phone conversations tinged with flirtation and plans for intimate rendezvous. Yeon-u emerges as a devoted partner, prioritizing So-jin above all else, even declining an invitation to a friend's wedding shoot. Mi-eun, anticipating his presence, is left with a pang of disappointment upon learning of his absence.
As So-jin's schedule fills with the thrills of dating, she inadvertently muddles her calendar, forgetting Gang-hun's memorial service until the eleventh hour. Rushing to make amends, she cancels her plans with Yeon-u and rushes to the cemetery, flowers in hand, to honor Gang-hun and his father. Meanwhile, Yeon-u attends his friend's event, unaware of the serendipitous twist fate has woven.
Fate seems to have a mischievous hand, as the location of Yeon-u's friend's shoot coincides with the spot where Gang-hun's father exchanged vows. The group decides to revisit the sacred ground, granting Gang-hun's father a moment of solitude. Unwittingly, Gang-hun and So-jin find themselves on a solitary stroll, only to cross paths with Yeon-u, Mi-eun, and their friends, painting a poignant picture of love, loss, and the intricate web of human connections.
So-jin endeavors to maintain a nonchalant facade, yet her irritation simmers beneath the surface as she witnesses Yeon-u and Mi-eun adorning matching Hanbok ensembles. Her annoyance intensifies when she catches Mi-eun assisting Yeon-u in removing an accessory from his head, a sight that stirs her jealousy.
Meanwhile, Yeon-u finds himself taken aback by So-jin's sudden cancellation of their date, citing Gang-hun's needs. Yet, he assures Mi-eun that he is unfazed, masking his true emotions. During the ride back, So-jin confesses her inner turmoil, yet she underpins her trust in Yeon-u, their bond forged by shared DNA.
The following day, a chance encounter at their usual food stall brings Mi-eun and Gang-hun face to face. Mi-eun, with a heartfelt nudge, urges Gang-hun to confess his feelings for So-jin before it slips away. Parallelly, So-jin's anxiety spirals as she observes more women drawn to Yeon-u during their dates, convinced that his notorious "Indecent Octopus" gene is at play. She is consumed by fear, her mind awhirl, barely registering his invitation to a movie date.
Mi-eun, too, finds herself unable to shake off thoughts of Yeon-u. She seeks So-jin's counsel, and after their session, offers sage advice. Drawing from her intimate knowledge of Yeon-u, she reveals her subtle connection, even wearing a shoe reminiscent of the one he gifted So-jin. She emphasizes that Yeon-u thrives in relationships where he is not restrained or pressured.
Mi-eun's words and So-jin's relentless worries about Yeon-u's infidelity-prone genes converge, pushing our scientist to the brink of revelation. After a pivotal conversation with A-ri, she experiences a eureka moment and embarks on creating a serum tailored to refine Yeon-u's genetic makeup. Her goal: to dampen his cheating tendencies and awaken his innate monogamous instincts. With determination, she presents him with the serum, entrusting him to apply it regularly, in hopes of forging a future grounded in trust and loyalty.
Their paths eventually intertwine at a cinematic rendezvous, where So-jin finds herself constantly in a comedic spiral of self-embarrassment, her antics providing an endearing charm. Parallelly, Jung-tam and Sung-mi embark on their own date, only to stumble upon a mild disagreement centered around Sung-mi's perceived lack of sensitivity. Fortunately, this is but a fleeting observation from Jung-tam, a mere ripple in their otherwise placid waters.
Meanwhile, A-ri's journey takes a poignant turn as she ventures to the church after a long day, confiding in Father Andrea the weight of her past trauma. Her tale unfolds, revealing a dark chapter from high school where she and her friend, Yoon-hye, were relentlessly bullied. One fateful night during a school excursion, the bullies' brutality escalated, targeting Yoon-hye and leading her to the rooftop. Amidst the terror, A-ri sought refuge in a closet, unable to bear witnessing the horrors that unfolded. The loss of Yoon-hye that night has haunted A-ri, burdening her with guilt for not stepping forward. Father Andrea, with gentle wisdom, absolves her of this self-imposed blame, urging her to seek happiness amidst the shadows.
Elsewhere, Yeon-u's world shatters as his father officially severs ties with his mother. Jang-mi's pleas for reconciliation fall on deaf ears, her husband's suspicion of her involvement in the death of his mistress and unborn child a formidable barrier. In the midst of his own emotional turmoil, Yeon-u receives this devastating news from Jang-mi during a fleeting moment of intimacy with So-jin. Despite his attempts to hide his distress, So-jin senses the shift, though he assures her all is well. Seeking solace, Yeon-u retreats to Gang-hun's father's restaurant, drowning his sorrows in alcohol as he pours out his heart to Gang-hun. His facade of indifference towards his parents' divorce crumbles, revealing the profound pain he bears from witnessing his mother's suffering. While acknowledging the divorce may be best for her, Yeon-u still feels a profound sense of unease. Gang-hun offers comfort, deeply moved when Yeon-u declares his disbelief in destiny yet his fervent desire to make So-jin his own.
The next dawn brings a surprising turn as Mi-eun takes a bold step, visiting Yeon-u unannounced. Finding him preparing for the day, he warmly welcomes her, her gift of abalones a welcome distraction. Mi-eun harbors a confession, yet their conversation is abruptly halted by a bubbly video call from So-jin, her excitement an unexpected interruption to the poignant moment.
So-jin eagerly anticipated inviting Yeon-u over for breakfast, a meal she had meticulously prepared alongside Gang-hun. Her excitement was abruptly shattered when Mi-eun unexpectedly appeared, greeting her with a smile that left So-jin flustered. She hastily feigned composure, abruptly ending the call with a pretext of an impending jog, her heart racing.
A-ri and Gang-hun couldn't help but feel agitated by the sudden turn of events. A-ri's curiosity piqued, wondering aloud why Mi-eun would be at Yeon-u's doorstep so early, unless she had spent the night. So-jin, fiercely protective of Yeon-u, struggled to conceal her mounting anger as she darted out the door, the heavens opening up with a downpour as if mirroring her emotions.
Gang-hun, sensing her distress, pursued her, only to find himself in a race with Yeon-u, who was equally determined to reach So-jin. So-jin, her phone silenced, remained elusive, ignoring their frantic calls.
Fatefully, Yeon-u caught sight of her first, sprinting towards her like a beacon of hope amidst the storm. Their encounter was a catharsis of emotions, with So-jin unleashing her pent-up anger while Yeon-u pledged to unravel the mysteries that had caused her distress. He begged for her trust in the depth of his feelings, and as they found solace in each other's embrace, Gang-hun, witnessing the scene from afar, felt a pang of defeat.
This marked the third time Gang-hun had arrived too late to be the first to comfort So-jin. The realization dawned on him that he was consistently lagging behind when it came to her, a bitter truth that weighed heavily on his heart. Though he regretted his timing, he doubted that confessing his feelings would alter their dynamic. In a moment of despair, he sought solace in alcohol, wandering to the park where their childhood memories intertwined, seeking answers amidst the memories of a simpler time.
