Episode 12 of "Love Your Enemy" kicks off with a poignant flashback to a fateful twelve years prior, where Yoon Ji-won's father uncovered Gyung-hoon's clandestine theft of company funds. Desperate for assistance, he sought the aid of Seok Ji-won's father, but was met with a cold refusal. En route back to confront Gyung-hoon, Yoon's father's path tragically crossed with Gyung-hoon's, both ensnared in a grim accident. In a moment of moral decay, Gyung-hoon chose to ignore his duty to save and tampered with the dashcam evidence, erasing any trace of his culpability.
In the unfolding present, Jae-ho, amidst his own battle with illness, stumbles upon the truth but, clouded by his condition, momentarily confuses Gyung-hoon for his beloved son. As Gyung-hoon flees, with Seok Ji-won hot on his trail, the police intervene, leaving Yoon Ji-won to comfort her frail grandfather.
At the hospital, Jae-ho's diagnosis of cognitive decline, teetering on the brink of dementia, is revealed, though mercifully less severe than initially feared. Meanwhile, Gyung-hoon faces the severest penalties, his crimes finally catching up with him.
As summer vacation dawns, Mun-soo embarks on a journey outside the city, driven by a rekindled passion for swimming. Elsewhere, Soo-ah and Dr. Hong's burgeoning romance blossoms, as they plan an intimate dinner together.
In a poignant confrontation, Jae-ho confronts Gyung-hoon, expressing deep regret for mentoring him. This poignant encounter serves as a catalyst for Jae-ho and Seok Ji-won's father to finally lay their long-standing rivalry to rest. Jae- ho offers heartfelt gratitude to the Seok family, while Seok Ji-won's father is consumed by guilt over Jae-ho's son's untimely demise, a tragedy that unfolded shortly after his refusal to lend a helping hand twelve years ago.
With their familial feud resolved, the Seok and Yoon families embark on a comical spat over the intricate details of the wedding. However, just when tensions threaten to escalate, Seok Ji-won's grandmother, Jae-ho's former love interest, arrives like a soothing breeze, calming the stormy waters and restoring harmony.
A few days passed swiftly: Seok Ji-won arrived tardily to their pre-wedding photoshoot, but was immediately captivated by Yoon Ji-won's breathtaking beauty. To add a twist to the tale, the new couple's typical squabbles erupted after a thunderstorm wrecked their carefully planned shoot.
Meanwhile, at Dr. Hong's farewell bash, Soo-ah and Dr. Hong found convenient excuses to steal moments together, subtly revealing that they had embarked on a romantic journey. Elsewhere, Ji-hye, with a heart heavy with remorse, finally confessed to Seok Ji-won about her meddling in their high school days, earning his forgiveness and mending their friendship. Seizing the importance of their bond, Seok Ji-won and Yoon Ji-won made amends after their heated dispute.
Jae-ho and Seok Ji-won's grandmother shared a heartwarming bond over board games, reminiscing about cherished memories from the past. Separately, Seok Ji-won floated the idea of developing an ecological park in the city, instead of a golf course, to empower the local communities.
Subsequently, Seok Ji-won embarked on a month-long business trip to New Zealand, leaving a void in Yoon Ji-won's heart. Ji-hye, meanwhile, encountered a charming new math teacher who caught her attention. Jae-ho, on the other hand, transformed into a seasoned advisor for the ecological park project nestled in the nearby mountains.
Yoon Ji-won's longing for Seok Ji-won intensified during Christmas, prompting her to venture to Namsan Tower amidst the falling snow. To her amazement, she found Seok Ji-won awaiting her there, vowing never to abandon her again. Flashing back to their childhood, the scene depicted them playing house, where a young Seok Ji-won had categorically refused to marry Yoon Ji-won. However, young Yoon Ji-won had confessed her feelings, attempting to persuade him with a tender kiss on the cheek. Returning to the present, Seok Ji-won and Yoon Ji-won embraced warmly, bringing the episode to a heartfelt close.
