Episode 6 of "Love Next Door" kicks off with a heartfelt reminiscence from Seung-hyo, as he fondly recalls each of Seok-ryu's pivotal firsts—the thrilling moment her first tooth fell out, the triumphant ride on a bicycle sans assistance, the mischievous escapade of running away from home, the blush-inducing confession to a senior in high school, and the momentous engagement. The narrative shifts as Seok-ryu gracefully delivers side dishes to Seung-hyo's abode, where after greeting his parents warmly, she ascends the stairs in search of him. Unwittingly, she stumbles upon a letter penned by Seung-hyo during his high school days, while he is engrossed in his shower. Upon catching her in the act, he swiftly snatches the letter, crumples it into a ball, and dismissively tosses it into the bin, downplaying it as mere jest. Sensing the subtle tension, Seok-ryu tactfully changes the subject and departs for her father's restaurant.
At the restaurant, Seok-ryu shares her cherished memories of visiting as a child and the joy it brought her. However, her father's demeanor betrays a hidden agenda, shrouding him in an aura of secrecy rather than joy.
Following the letter's revelation, Seung-hyo withdraws into a shell of distance. Seok-ryu's chance encounter with Tae-hue is brief, as Seung-hyo's insistence on their work obligations hastens her departure.
Later, Seok-ryu's meeting with Mo-eun unveils the latter's ambitious dream of being dispatched to the South Pole. To bolster her chances, Mo-eun has embarked on learning to navigate a boat. She, in turn, inspires Seok-ryu to pursue her culinary passion, encouraging her decision to enroll in a cooking class. Together, they extend an invitation to Seung-hyo to celebrate Seok-ryu's newfound pursuit, but he politely declines.
As the night deepens, Seung-hyo chances upon Dan-ho and extends an invitation for a drink. However, their evening evolves into a sober soirée spent at Dan-ho's abode. During this unexpected gathering, Seung-hyo even meets Dan-ho's daughter, introducing himself with a warm smile as her father's "neighborly friend," adding a touch of heartwarming intimacy to the evening.
Sensing the troubled aura emanating from Seung-hyo, Dan-ho delicately delves into his concerns with empathy. Seung-hyo, in a roundabout manner, confides in the complexities of his feelings for Seok-ryu. He reveals that while his heart yearns for her, the fear of shattering their cherished friendship, forged over years of camaraderie, looms large. Dan-ho, drawing from Seung-hyo's past bravery during the swimming competition, encourages him to summon that same courage now.
Meanwhile, Mo-eun, with mischievous intent, eavesdrops on their intimate exchange, her smirk revealing her secret knowledge. It transpires that she had already uncovered Seung-hyo's sentiments, having stumbled upon and deciphered their letters in the time capsule.
Elsewhere, Seok-ryu embarks on her maiden voyage into the world of cooking classes. Later, as the night wears on, Seung-hyo, chance encountering his old teammates, stumbles upon a startling sight—Seok-ryu's father assisting a drunken woman. Their subsequent conversation leads to a request from Seok-ryu's father, beseeching Seung-hyo to shield the truth from his wife's prying eyes.
The following day, Seok-ryu's mother and her circle of friends gather at Mo-eun's mother's office, where whispers of discontent linger. Seok-ryu's mother shares her disquietude over her husband's untimely returns, sparking suspicion among her peers about a potential extramarital affair. They counsel vigilance, and soon, Seok-ryu's mother, driven by suspicion, rummages through her husband's belongings, uncovering the shocking truth of a loan and unauthorized withdrawals from their joint account.
In a serendipitous twist, Mo-eun and Dan-ho's paths unexpectedly cross at the convenience store. Mo-eun, with a hint of warning, cautions Dan-ho against sacrificing all for his daughter, drawing from her own bitter experiences as an only child who resented her mother's relentless dedication. She further implores his assistance in reclaiming Yeon-du's affections. As Dan-ho regales her with anecdotes of Yeon-du's preferences, alcohol clouds his senses, rendering him incapable of staying awake. Mo-eun, unfazed, promptly deposits him, quite literally, at the doorstep of his home, which conveniently abuts hers.
As Seok-ryu's father trudged home, he was met with a dire situation. It transpired that a group of patrons at his restaurant, who had feigned possession of a popular YouTube channel, had lodged a complaint, alleging the presence of hair in their meals. Upon his arrival to address the issue, chaos ensued as one of the guests' watches was inadvertently damaged. They pressed for compensation, exorbitant for the supposed luxury timepiece, and ominously threatened to unleash a viral video exposing the hygiene mishap.
Haunted by the guilt and burden of this ordeal, Seok-ryu's father had resorted to moonlighting as a taxi driver, striving to make amends. Overwhelmed by a sense of inadequacy in the face of his family, he retreated, leaving Seok-ryu to console him in his wake.
The following day, Seok-ryu embarked on a mission to uncover the truth, only to find Seung-hyo already ahead of the game. He confronted the culprits, exposing their ruse as cunning extortionists who had deliberately planted hair in the food and concocted a false narrative around a non-existent YouTube channel. Shockingly, the damaged watch was revealed to be a cheap imitation, adding insult to injury. With their scheme unraveling, the two scoundrels fled, pursued relentlessly by Seung-hyo and Dan-ho, who had joined the chase. With the combined efforts of Seok-ryu and her brother, they finally cornered the perpetrators.
Grateful for Seung-hyo's intervention, Seok-ryu expressed her thanks, but he sternly reminded her that they were no longer children and discouraged her persistent pursuit. As the night deepened, Seok-ryu's thoughts drifted back to Seung-hyo's formative moments in Korea—his maiden Korean meal, the thrill of taking his first dip in water, and the flutter of his first crush, though its identity remained a mystery to her.
The subsequent day, after her cooking class, Seok-ryu eagerly awaited Seung-hyo's arrival, eager to present him with a dish she had carefully crafted—a recreation of his very first Korean meal, which had also become his favorite. However, her gesture was met with a fiery rebuke as Seung-hyo implored her to cease her relentless pursuit. Hurt and perplexed, Seok-ryu lashed out, insisting on their friendship and her right to meddle in his affairs.
Amidst the heated exchange, she probed him about a previous statement, leaving Seung-hyo in a precarious position as the possibility of his hidden feelings for Seok-ryu being exposed loomed large, marking a tense cliffhanger to the episode.
