The drama opens in the childhood days of the tennis prodigy LEE GUN, who’s just one point away from winning the World Junior Championship. His younger brother LEE SHIN serves as his ball kid, cheering his hyung on from the sidelines. At the pivotal moment, the opponent’s racket slips from his hand, soaring straight toward Shin. Instinctively, Gun leaps to shield his brother, taking the brunt of the impact — and though he wins gold, the injury irreversibly alters the trajectory of his life.

All grown up now, Gun (Kim Jae-joong) rewatches the video of his match while on a plane with his family. At the first class bar, fellow passenger KYUNG JOO-YEON (Jin Se-yeon) overhears Gun’s self-pitying lamentations, typing up an armchair diagnosis on her tablet PC. They’re equally all up in their heads, with Joo-yeon mistakenly assuming Gun is flirting with her — when really all he wants is to point out her lipstick has smudged. A sudden bout of turbulence sends Gun’s thumb landing right on Joo-yeon’s lips, and then she lets him fall to the floor in order to save her tablet from shattering. LOL, these two are a mess.

Gun and Joo-yeon’s mishaps don’t end there. While distracting the horde of reporters and fangirls in tennis star Shin’s place, Gun accidentally crashes into Joo-yeon again, unknowingly mixing up their identical luggages. Then he realizes his family’s car has accidentally driven off without him, not even noticing he hadn’t boarded.

A heartbreaking flashback shows that Gun’s parents had left him with his grandmother for a few years, so that he wouldn’t have to endure through watching Shin practice tennis without him. While chasing after his parents’ taxi, Gun had dropped his medal into a lake, then fallen in after it — and a young girl had saved him from drowning.

In the present day, poor Gun is the black sheep of the family. His parents fawn over the golden child Shin (Lee Jong-won!), catering to his every need, while Gun deals with Mom (Yoon Yoo-seon) barging in for the kimchi refrigerator in his bedroom. Needless to say, Gun thinks about as highly of himself as others do of him — that is to say, not at all. Amidst his horrible day, he can’t muster up the energy to answer Joo-yeon’s frantic calls asking for her luggage back.

Gun’s trauma manifests in phantom pains that plague his right hand, and that’s how he crosses paths with Joo-yeon again. She’s a psychiatrist, and she diagnoses his ailment with a cold pragmatism — it’s all in his head. Her words come across as dismissive of Gun’s predicament, but once she reviews his case file, she leaves him a sincere voicemail clarifying her stance and validating his pain.

See, Joo-yeon’s latest research project is a pioneer study, proposing a neurosurgery that can remove negative memories. In other words, a “Bad Memory Eraser.” Despite starting off on the wrong foot with Gun, she can’t help but feel sympathetic to his plight.

That is, until the latch of the cage transporting her team’s lab rat comes undone, and the poor animal winds up crushed under Gun’s tire. Devastated that months of painstaking research have just gone up in smoke, Joo-yeon lashes out at the dismissive Gun, lecturing him for undervaluing a precious life. “Have you ever been a meaningful person to anyone?” Joo-yeon criticizes. All he’s doing is wallowing in his own self-pity.One rat funeral later, Joo-yeon boldly asks the conference panel to permit a second trial — but on a human this time. Coincidentally, that night, the perfect test subject arrives. Gun is wheeled into the hospital, unconscious and bleeding profusely after jumping off a bridge.

Shin is acquainted with Joo-yeon’s senior teammate HAN DONG-CHIL (Kim Kwang-gyu), whom he’s secretly receiving prescription medicine from, presumably for his camera anxiety. Having inadvertently caught a glimpse of Joo-yeon’s research files on Dong-chil’s desk, he desperately entreats Dong-chil to save his brother.

Joo-yeon watches the surgery, guilt-ridden over her last words to Gun. The operation turns out to be a success — but when Gun wakes up, his mind has superimposed Joo-yeon onto the image of his childhood first love, and he greets her by pulling her into a hug. That isn’t the only peculiar side effect, though. Gun’s memory loss has resulted in a 180-degree personality shift, and he’s now overflowing with confidence, strutting around like a proud peacock. Noooo, the secondhand embarrassment! *cringe*

Gun’s flamboyant poise may raise a few eyebrows, but it’s still miles better than the browbeaten meekness of before. In an attempt to protect his brother from the painful truth and explain away his amnesia, Shin fibs that Gun simply fell down the stairs. As for Joo-yeon, she’s faced with the potential ruin of her clinical trial should news of the peculiar side effect spread. Yet the alternative is to play into Gun’s misattributed fantasy, and Joo-yeon isn’t quite sure which fate is worse.

Alas, Gun’s memories aren’t likely to stay repressed forever. An offhand mention of his lost medal sends him right back into the hospital with a sharp pain piercing his head, prompting flashbacks that shed further light on Gun’s suicide attempt. At his elementary school reunion, Gun had found his long-lost medal hung on the Christmas wishing tree. Giddy with the prospect of reuniting with his first love, he’d chased after her, only to find her kissing Shin in the carpark — reinforcing how he’s always losing everything he’s ever had to his little brother.

Mom confesses as much to Joo-yeon, when the doctor finds her crying next to a sleeping Gun, guilt-ridden over her callous treatment of him before. The night of his Han River plunge, he’d repeatedly snatched the crab Grandma sent him off the plates Mom offered to Shin, then finally blew up at his family regarding their blatant favoritism. When Mom harshly reprimanded him, Gun delivered the cold hard truth — she may be a mother to Shin, but she’s never been a mother to him.

That night, Gun wanders onto the hospital tennis court, where Joo-yeon finds him unconsciously shedding tears. Just then, the ball machine shoots, and Gun whirls her around, catching the ball with his right hand. Realizing that Gun is finally able to use his hand again, Joo-yeon resolves not to render his progress futile. “You can always start over,” she reassures. “Whether it’s sports, or love. That’s right. I’m your first love.”This show may seem wacky and shallow at first glance, but it also revisits earlier scenes to recontextualise characters’ actions, adding pathos to their motivations. Gun complains that Mom only cooks healthy boiled chicken for Shin’s sake, but the next day, she makes grilled chicken for him. The up-and-coming tennis player CHA SHI-ON (Lee Ruby) has a photo of young Gun as her phone wallpaper, proving her words about looking up to him as her inspiration.

As for Shin, he may seem content to bask in the spotlight at his brother’s expense, but after his agency director demeans Gun in front of everyone, Shin immediately threatens to terminate his contract. It’s echoed in the scene where a post-op Gun mistakenly takes over Shin’s room, and Shin simply lets him, immediately clearing away his own photos. These characters may have failed Gun in several ways, but they’re standing up for him too, in ways he does not realize. Next episode coming very soon so stay tuned.

This summary paints a compelling picture of "Bad Memory Eraser," which appears to blend heartfelt drama with touches of humor and fantasy. The characters are layered, with deep emotional ties and conflicting motivations, making the show not just about a "memory eraser" but also about family dynamics, self-worth, and the lasting impact of childhood trauma.

LEE GUN’s journey is particularly poignant. Once a promising tennis prodigy, his injury and subsequent sidelining have left him feeling overshadowed by his younger brother, LEE SHIN, whose career has only flourished. Gun’s struggles with self-worth, accentuated by his family’s favoritism toward Shin, create a compelling backdrop for the emotional and psychological exploration that unfolds.

KYUNG JOO-YEON, a psychiatrist with her own set of complexities, adds an intriguing layer to the narrative. Her involvement in pioneering neurosurgery to erase bad memories creates a moral dilemma—can we truly heal by forgetting, or does the pain of memory serve a purpose in shaping who we are? Her relationship with Gun begins as a series of unfortunate misunderstandings but evolves into something much deeper as she becomes more involved in his life and recovery.

The transformation in Gun’s personality following the surgery is a fascinating twist. His newfound confidence and misattributed love for Joo-yeon introduce both comedy and tension, as it complicates the already tangled web of relationships. The show seems to delicately balance these moments of levity with the darker undertones of Gun’s mental health struggles, particularly his suicide attempt, which brings the gravity of his situation into sharp focus.

The supporting characters, like Shin and their mother, add further depth to the story. Shin’s internal conflict between his success and the cost it has had on his relationship with Gun is subtly portrayed, while their mother’s guilt and her attempts, however misguided, to connect with Gun reflect the complexities of familial love.

The narrative also appears to use flashbacks effectively, recontextualizing characters’ actions and revealing hidden motivations. This technique not only deepens the audience’s understanding of the characters but also adds an element of suspense as past and present events slowly intertwine.

"Bad Memory Eraser" seems to offer a rich blend of drama, humor, and psychological insight, exploring themes of identity, family, and the human need for validation. It’s a story about starting over, facing one’s past, and the possibility of healing, all wrapped up in a plot that’s as quirky as it is touching.

As Gun continues to adapt to his new, bold persona, his altered behavior begins to ripple through his life and relationships. The episode opens with Gun strutting confidently into a meeting with his family's business partners, a stark contrast to the quiet, hesitant man they once knew. His brashness both impresses and unsettles those around him, particularly his parents, who are unsure of how to react to this "new" son. Meanwhile, Shin is quietly torn between relief at seeing Gun more confident and anxiety over what this change might mean for their delicate brotherly bond.

At the hospital, Joo-yeon is grappling with her own conflicting emotions. She's relieved that the surgery seems to have had positive effects on Gun's self-esteem, but she's also deeply concerned about the ethical implications. Gun’s misplaced affection for her, rooted in the memory of his childhood first love, is becoming increasingly difficult to manage. During a tense conversation with her senior, HAN DONG-CHIL, Joo-yeon confesses her fears that they might have meddled too deeply in Gun’s psyche. Dong-chil, however, remains pragmatic, focusing on the success of the surgery and urging Joo-yeon to keep Gun’s condition under wraps until they can better understand the long-term effects.

Back at home, Gun’s newfound assertiveness leads to further friction with his family. When his mother tries to prepare a meal for Shin, Gun interrupts and insists on cooking instead. The awkward meal that follows is full of tension, with Gun making pointed comments about the family’s history of favoritism. His mother’s attempts to make amends fall flat as Gun, emboldened by his new persona, refuses to let old wounds heal so easily.

The real conflict of the episode arises when Gun decides to return to the tennis court. With memories of his past injury suppressed, he believes he’s ready to pick up the racket again. Joo-yeon, who has been trying to distance herself from Gun, finds herself drawn back into his orbit when he calls her to watch his first practice match. Reluctantly, she agrees, worried about what might happen if Gun's memory begins to resurface in this environment.

On the court, Gun’s initial performance is nothing short of miraculous. His hand, once plagued by phantom pains, moves with newfound agility and strength. For a moment, it seems like he might actually make a comeback. But as the match intensifies, flashes of his past trauma begin to bleed into his consciousness. The sight of a ball soaring towards him triggers a vivid flashback to the day he protected Shin, and Gun freezes, overwhelmed by the sudden onslaught of memories.

Joo-yeon rushes to his side, but it’s too late. Gun collapses, clutching his head in pain, the memories of his injury crashing back with full force. The episode ends on a cliffhanger as Gun, lying on the court, mutters disjointedly about his lost medal, his forgotten love, and his deep-seated resentment toward his brother. Joo-yeon, kneeling beside him, realizes that the effects of the surgery are unraveling faster than she anticipated, leaving her torn between her role as a doctor and her growing emotional involvement with Gun.

As the credits roll, viewers are left wondering whether Gun will be able to reconcile his fractured memories with his new identity, or if the pressure of his resurfacing trauma will shatter the fragile progress he’s made. Episode 3 sets the stage for an intense psychological battle, where the lines between reality and memory blur, and the true cost of tampering with the mind’s natural processes begins to reveal itself.

**Scene 1: The Fractured Mind**

Episode 5 opens with Gun still on the hospital rooftop, gazing out at the cityscape as the first light of dawn breaks through the clouds. His mind remains in turmoil, with fragmented memories flashing across his consciousness like shards of broken glass. We see glimpses of Gun's past, from the fateful day of his injury to his deep-seated resentment toward his brother Shin. Each memory is tinged with pain, confusion, and the overwhelming sense of loss that has haunted Gun for years.

As the sun rises, Gun is interrupted by the arrival of Joo-yeon, who has been anxiously searching for him. She cautiously approaches him, sensing the fragile state of his mind. Their conversation is tense and emotionally charged, with Gun expressing his frustration at the instability of his memories and the unpredictable nature of his emotions. He questions the purpose of continuing with life if he can no longer trust his own mind.

Joo-yeon, trying to balance her professional responsibility with her growing personal feelings for Gun, gently reassures him that the journey to recovery is never a straight path. She emphasizes the importance of facing his past, no matter how painful, in order to move forward. This moment of vulnerability between them deepens their connection, but it also complicates Joo-yeon’s internal conflict about the ethical boundaries she’s been skirting.

**Scene 2: Family Ties and Emotional Strain**

Meanwhile, Shin is dealing with his own internal battle. His guilt over Gun's current state weighs heavily on him, and he begins to question the decisions that led to the experimental surgery. Flashbacks to their childhood show a different side of Shin—one where he idolized his older brother and struggled with the pressure of living up to the expectations placed on him. These scenes reveal that Shin's success was not just a product of his own talent but also the result of the burden he felt to make up for Gun's lost potential.

Back in the present, Shin confronts his parents about their favoritism. This confrontation is a pivotal moment in the episode, as it forces the family to confront the deep-seated issues that have been festering for years. His mother, who has always been more openly affectionate toward Shin, breaks down as she realizes the extent of the damage her actions have caused. The father, typically stoic, admits that he never knew how to handle the situation and chose to focus on Shin because it was easier than addressing Gun’s trauma.

The family’s conversation is raw and emotional, with each member laying bare their regrets, fears, and hopes for the future. They acknowledge the mistakes they've made but also express a desire to make amends. For the first time, there’s a glimmer of hope that they might begin to heal as a family, although the path ahead remains uncertain.

**Scene 3: The Shadow of the Past**

As Gun continues to grapple with his returning memories, he becomes increasingly obsessed with understanding the full scope of his past. He spends hours watching old home videos, looking for clues that might explain the fractures in his memory. In one particularly poignant scene, Gun watches a video of himself as a young boy, eagerly practicing tennis while his father films him. The boy on the screen is full of life and ambition, a stark contrast to the man Gun has become.

These scenes are interspersed with more flashbacks, showing the gradual decline of Gun's relationship with his parents and Shin. We see moments of jealousy, misunderstanding, and missed opportunities for connection, all of which contribute to the deep emotional wounds that Gun carries with him. These flashbacks are critical in illustrating how each small incident built up over time, leading to the resentment and pain that now define Gun’s interactions with his family.

At the same time, Gun begins to experience more vivid flashbacks of the mysterious girl who saved him from drowning in the lake all those years ago. He becomes fixated on uncovering her identity, convinced that she holds the key to understanding his current predicament. This obsession drives a wedge between him and Joo-yeon, who is increasingly frustrated by Gun's refusal to focus on the present instead of chasing after ghosts from his past.

**Scene 4: The Ethical Dilemma**

Joo-yeon is also facing her own crisis. The deeper she becomes involved in Gun’s life, the more she questions the ethical implications of her work. Her relationship with Gun has crossed professional boundaries, and she is haunted by the fear that she has caused more harm than good. This inner turmoil comes to a head during a tense meeting with her mentor, Han Dong-chil, who remains steadfast in his belief that their research is groundbreaking and that any setbacks are simply part of the process.

However, Joo-yeon is no longer convinced. She starts to see the “Bad Memory Eraser” project not as a groundbreaking medical advancement, but as a dangerous experiment with the potential to cause irreparable harm. Her mentor’s cold pragmatism clashes with her growing empathy for Gun, leading to a heated argument where Joo-yeon accuses Dong-chil of being more concerned with the success of the project than with the well-being of their patients.

This argument marks a turning point for Joo-yeon. She decides to step back from the project, realizing that she can no longer justify her involvement if it means compromising her integrity. She informs Dong-chil of her decision, leaving him shocked and frustrated. Joo-yeon’s departure from the project represents a significant shift in her character, as she begins to prioritize her own values over the pressure to achieve success in her field.

**Scene 5: A Glimpse of Redemption**

As the episode progresses, Gun’s relationship with his family begins to show signs of improvement. After their emotionally charged conversation, his parents make a genuine effort to reconnect with him. They start by making small gestures, like cooking his favorite meals and spending time with him, but these actions are laden with unspoken apologies and the hope of reconciliation.

Shin, too, begins to take steps toward repairing his bond with Gun. He invites Gun to one of his tennis matches, hoping to share his success with his brother in a way that doesn’t feel like gloating. Gun, still struggling with his feelings of inadequacy, hesitantly accepts the invitation. At the match, Gun is surprised to find himself genuinely enjoying the game, even cheering for his brother. This moment of joy is fleeting, but it signifies a potential turning point in their relationship.

However, the progress is fragile. After the match, Gun overhears a conversation between Shin and his coach, where Shin expresses his frustration at constantly being compared to Gun. Although Shin's words are not meant to be hurtful, they reignite Gun’s insecurities, reminding him of all the ways he feels he has failed. This setback highlights the ongoing tension between the brothers and the challenges they face in moving past their complicated history.

**Scene 6: The Unraveling**

As Gun’s memories continue to resurface, he becomes increasingly unstable. The return of his trauma, coupled with the confusion of his new reality, pushes him to the brink. His behavior becomes erratic, oscillating between moments of clarity and episodes of intense emotional outbursts. These outbursts are particularly alarming for Joo-yeon, who begins to fear that the surgery has caused irreversible damage.

Gun’s condition worsens to the point where he begins to hallucinate, seeing his younger self and the mysterious girl from the lake in his everyday surroundings. These hallucinations blur the line between past and present, leaving Gun disoriented and terrified. In one particularly intense scene, Gun lashes out at Shin, accusing him of stealing his life and leaving him with nothing. Shin, deeply hurt but understanding of Gun’s state, does his best to comfort him, but the gap between them feels insurmountable.

The episode reaches its climax when Gun has a complete mental breakdown. Overwhelmed by the flood of memories and the weight of his unresolved emotions, he isolates himself in his childhood home. Joo-yeon and Shin, both deeply concerned, rush to find him. When they arrive, they find Gun in the midst of a hallucination, reliving the day of his injury as if it were happening in real-time. He’s holding a tennis racket, swinging it wildly as he tries to fend off an imaginary opponent.

Joo-yeon carefully approaches him, using a calm and soothing tone to try and bring him back to reality. She talks him through the memory, reminding him that he’s no longer that scared little boy and that he has the strength to face his past. Shin, watching from the sidelines, is overcome with emotion, finally realizing the extent of the trauma that Gun has carried with him all these years.

**Scene 7: A New Beginning?**

With Joo-yeon’s help, Gun slowly begins to come back to himself. He drops the racket and collapses into her arms, sobbing uncontrollably. This breakdown is a cathartic moment for Gun, as he finally allows himself to feel the full weight of his emotions rather than repressing them. Joo-yeon holds him, offering the comfort and support that he’s needed for so long.

The episode ends on a somber yet hopeful note. Gun is far from fully healed, but for the first time, he feels like he’s not facing his demons alone. His relationship with Joo-yeon, while complicated, offers him a sense of stability and understanding that he’s never had before. Meanwhile, Shin and