Episode 5 of "Bad-Memory Eraser" commences with an amusing misunderstanding, as Gun mistakenly accuses Ju-yeon of pilfering his suitcase. Her swift clarification reveals it to be hers, and her motive: a thoughtful quest to locate his ID card, sparing him any inconvenience. His heart swells with warmth at her concern, and together, they uncover the elusive document. As his blistered hand throbs in pain, she tenderly applies a bandage, assuring him that as his physician, she stands by his side unwaveringly. His response is equally endearing, confessing his allegiance to her and their playful banter fills the air with laughter.
Elsewhere, Shin is beset by a delusional belief that Sae-yan harbors romantic feelings for him. Little does he know, her persistent attempts to reach him stem from the loss of her bracelet in his vehicle. Her frustration mounts as he dismisses her intentions as mere pretext, and as he departs, he senses a shadowy presence trailing him.
Ju-yeon, meanwhile, struggles to shake off the intensity of Gun's gaze, her conscience plagued by the impending heartbreak she's sure to inflict. Amidst Tae-oh's presence, Gun's attempt to present her with a flower is foiled by its untimely breakage, leaving her unamused. The arrival of Guk-bong heralds a new development, as Gun unveils his ambitious plan to secure Chairman Won, a colossal investor in biotechnology and sports, as a financial backer. The enigmatic Won remains unseen, shrouded in mystery, with an exceedingly selective agent guarding his every move.
At the hospital, Sae-yan overhears a snide remark about Ju-yeon being excluded from a staff dinner due to her perceived aloofness. Incensed, she defends Ju-yeon by abruptly inviting her to join them. As they embark on a grocery run, Ju-yeon muses that work and friendship often walk parallel paths, never intersecting. Sae-yan, however, champions the beauty of fleeting connections and the unapologetic display of emotions. Ju-yeon hesitates, her thoughts racing, prompting Sae-yan to speculate about a hidden boyfriend, unaware of the emotional turmoil brewing within her friend's heart.
At the hospital's hushed corridors, Shin and Gun embarked on a fruitless quest for Ju-yeon, their steps echoing the emptiness of their search. Eventually, Shin, his weariness palpable, opted to rest in Gun's room, where the latter gazed at him intently, memories of childhood flickering in his eyes. As a child, Shin had clung to Gun like a shadow, seeking solace in his presence even during slumber. Shin's expression betrayed a mix of emotions, assuming Gun held no fond recollections of their bond.
Gun, sensing the undercurrents, probed delicately about their adult relationship, only to find it mirrored their youth—Shin, still attached, while Gun mischievously played tricks. The moment teetered on significance as Gun seemed poised to impart something weighty, yet he merely coaxed Shin to rise and extinguish the lights, a subtle gesture that spoke volumes.
Meanwhile, Sae-yan presented Ju-yeon with matching couple's tees, a token meant for her lover's hands. Ju-yeon feigned annoyance but plotted to bestow the gift upon Tae-oh, her thoughts straying from the intended recipient.
In the courtroom's stifling atmosphere, Shin's exhaustion was palpable. Mrs. Lee, her ministrations tender, noticed the crimson blisters marring his feet, igniting a fierce indignation towards Hong. Hong attempted to justify it as the inevitable cost of securing sponsorship for Shin's coaching endeavors, but Mrs. Lee's fury was unyielding. She stormed into the sponsor's office, shredding the contract into pieces, her anger a testament to her unwavering loyalty.
Elsewhere, Shi-on's world was turned upside down when her commercial was abruptly canceled, the aftermath of her injury and rehabilitation casting a pall. Gun, a pillar of strength, reassured her, his words a beacon of hope. Yet, time was not a luxury they could afford; Shi-on's mother demanded a down payment within ten days, the deadline hanging precariously over their heads.
As the next trial test approached, Gun's liberation was imminent, and Ju-yeon, his medical guardian, accompanied him to a racetrack, her curiosity a relentless companion. There, her inquisitiveness overcame her, leading her into a surprising exchange. She boldly declared her faux romance with Tae-oh, since their encounter in the UK, painting him as her maiden love. Little did she know, Gun's true purpose at the racetrack was to secure vital investments for his burgeoning company, each move a calculated step towards his aspirations.
Encountering a wealthy investor on the verge of dismissing him, Gun cunningly forecasts the downfall of the investor's favored steed, number 5, and the triumphant rise of number 3. Introducing Ju-yeon as the team's physician, she validates Gun's prophecy with her keen observation of horse number 5's agitated demeanor, piquing the investor's curiosity. However, Gun maintains an air of exclusivity, requesting another appointment, leaving the investor intrigued.
Ju-yeon, herself in awe, ponders why Gun doesn't personally wager and secure the financial backing. As an athlete, he steadfastly refuses to exploit the sport, earning Ju-yeon's profound admiration for his ethical principles. Despite her attempts to reach Tae-oh via text, he remains unresponsive.
As Gun prepares to invite Ju-yeon to dinner, Tae-oh intervenes, summoning her to a meeting room under the guise of a rendezvous. Ju-yeon rushes, equipped with matching tees, only to discover that Tae-oh's true intention was to conduct a test on Gun for his neurosurgery paper, in a bid to impress Dr. Kim.
Elsewhere, heeding Sae-yan's counsel, Ju-yeon transforms the meeting room into a romantic setting, adorned with balloons and candles, eagerly awaiting Tae-oh. But fate plays a cruel trick as Tae-oh, following the test, promptly departs to meet Dr. Yeo, unaware of Ju-yeon's heartbreaking overhearing of his efforts to conceal their relationship. Devastated, Ju-yeon struggles to clear the room before Tae-oh's abrupt departure with Yeo.
A fleeting memory reveals Tae-oh's solemn promise to Ju-yeon, declaring the day of her return from the UK as the dawn of their relationship, confirming Ju-yeon's honesty in their romantic past. With the truth unraveling, Gun arrives, urging Ju-yeon to confront Tae-oh. Instead, her emotions boil over, lashing out at Gun, who retreats.
As Ju-yeon weeps while departing, Shin stumbles upon her, offering solace in the form of a ride and a comforting cup of coffee. He believes in the healing power of food, though his strict diet prohibits him from partaking. Ju-yeon insists, finding amusement in his clumsy attempt, and discovers Sae-yan's bracelet in his car, promptly returning it.
Meanwhile, Gun confronts Tae-oh with a stern warning, forbidding him from causing Ju-yeon any further harm. Disregarding Dr. Kim's fury, Gun secures his own discharge, leaving Tae-oh to blame Ju-yeon and prompting Kim to suggest excluding her from the paper.
Han vocally champions her, arguing that the research is hers to lead, yet Kim counterpunches with Tae-oh's groundbreaking neurosurgery paper, subtly pointing out the divergence in Ju-yeon's psychiatric focus. He further exposes a crucial detail: Gun's findings, when partnered with Ju-yeon, are clouded by personal sentiments, whereas neurosurgery demands impartial, objective results.
The following day, Tae-oh orchestrates a lunch invitation, subtly maneuvering Ju-yeon towards reconsidering the research's direction, from psychiatry's realm to neurosurgery's, all for the sake of the trial's success. Despite her inner turmoil, Ju-yeon hesitates, her silence betraying her disappointment as she trudges home. Her family's playful jabs about a potential suitor only add to her musing, as Sae-yan's mention of a boyfriend prompts her to shield her nephew's ears, a gesture that sparks a realization—Gun's abrupt turn from her the night Tae-oh caught them might have been a reaction to spotting the doctor with Yeo. Weighing the research's benefits, Ju-yeon resolves to shift her focus.
At the hospital, as she tidies Tae-oh's desk, her hands uncover the test results he conducted on Gun, igniting a storm of emotions. Feeling helpless in her inability to shield her patient, she spitefully dumps the contents back onto his desk. His arrival and admonishment for gracefulness only fuel her ire further. Memories of Yeo wearing Tae-oh's iconic Eiffel Tower necklace flash through her mind, prompting her to cast aside her own Eiffel Tower keychain in a fit of anger.
Meanwhile, Gun embarks on a new chapter, officially launching his agency amidst a whirlwind of familial chaos tinged with support. Shin's gesture of sending Sae-yan the unbroken bracelet evokes a tender memory of her proudly displaying Gun's medal at their class reunion. Her anger reignited upon spotting Shin, she chases him to his car, a flurry of emotions driving her actions. A passionate kiss, followed by a resounding slap and a final declaration of dumping him, leaves her triumphant and satisfied, only to accidentally drop the bracelet. Amidst this tumult, her thoughts drift towards Gun, hinting at a new beginning.
Gun, immersed in sorting through his old car, stumbles upon the reunion invitation, triggering vivid memories of chasing after Shin's car at the reunion. His mind races as Ju-yeon, drenched from the rain, suddenly appears at his doorstep, her request for shelter leaving him bewildered. Her bold proclamation as the team doctor for his agency rings out, marking a decisive turning point in Bad-Memory Eraser's fifth episode.
