Episode 3 of "Spring of Youth" opens with an intoxicated Sa Gye tightly embracing Kim Bom, a scene that coincidentally catches Tae-yang's eye. Fueled by rage, Tae-yang forcefully pushes Sa Gye aside, but finds him already in a deep slumber. With little choice, he reluctantly hoists the heavy Sa Gye up to their dormitory. By morning, Sa Gye seems utterly oblivious to the happenings of the previous night. Despite this, Tae-yang sternly warns him, brooking no further disrespect towards Bom. Later, Sa Gye hastily departs, rushing to Kang Seok-hee to confront him about his constant surveillance. Seok-hee, with a grave expression, cautions him that if he wishes to shield Bom from harm, it would be best for him to stay away from both the school and her. However, Sa Gye ignores the advice and instead sends a message to Cho Sang-heon, warning him to cease his obsession with Bom. He then begins shadowing Bom, even attending her applied music class, though he spends most of it in a slumber. After class, Bom is exasperated by his stalking, and after a heated exchange, she cleverly evades him.
Meanwhile, CEO Cho Sang-heon meets with Tae-yang's father, Seo Min-cheol, proposing a discussion about an incident six years prior. A flashback unveils the scene of Cho's fatigue-induced driving that caused another vehicle to roll over. Seo Min-cheol was also a passenger in the car, and both had indulged in a few drinks. Kim Bom's mother was the driver of the overturned vehicle, desperately calling for help, but knowing that aiding her would bring trouble for both of them, they chose to stand idly by. Now, Sang-heon reveals to Min-cheol that Sa Gye might have witnessed the accident. Furthermore, he had never informed Min-cheol that the deceased had a daughter. Learning that it was Bom's mother, Tae-yang's close friend, Min-cheol is utterly shocking. Even more astonishing for him is the revelation that these three young individuals now reside under the same roof.
At school, Sa Gye arrived with thrilling news for the band—they had been selected to headline the school festival's lineup. However, the atmosphere of excitement swiftly disintegrated as Sa Gye and Tae-yang embarked on a heated debate over who should assume the roles of band leader and lead guitar player.
As Tae-yang and Sa Gye's squabble escalated, Bom proposed an overnight trip as a means to diffuse the tension. Cho Ji-na graciously offered her van for the excursion, and with some persuasion, they convinced her to join them. Upon reaching the serene campsite, Sa Gye found himself shadowing Bom everywhere, a behavior that irked Tae-yang considerably.
During another contentious altercation between the two, the scuffle inadvertently sent Bom tumbling down a rocky slope and into the river. Despite his efforts, Sa Gye struggled to lift her from the water, while Tae-yang effortlessly rescued her. As Sa Gye exited the water, he stumbled and slammed his head against a rock, triggering a cascade of vivid flashbacks.
In his dazed state, Sa Gye witnessed Tae-yang preparing to administer CPR to Bom and, in a panic, dashed towards them. Unfortunately, his hurried momentum caused him to topple over Tae-yang, resulting in an accidental, involuntary kiss. Both boys were left bewildered and annoyed but agreed to put their differences aside for Bom's sake, who cleverly feigned illness with a convincing cough and cold.
She promptly appointed Sa Gye as the band's lead guitarist and tasked Tae-yang with selecting the song. For the role of leader, she selflessly stepped into the breach herself. Just then, Gyu-ri burst in, brimming with concern. However, her passionate tirade accidentally revealed that Bom was an exceptionally skilled swimmer. The boys realized with amusement that her pretend illness was a clever ploy to unite them.
That evening, as the group basked in camaraderie around the crackling campfire, Ji-na secluded herself within the cozy confines of the camper van, flipping through Bom's meticulously kept notebook. Her eyes lit up upon discovering a fresh, unfamiliar melody, which she hastily concealed upon Bom's unexpected reentrance.
The following dawn, Seo Min-chul paid a visit to Kim Ja-young, requesting to retrieve Tae-yang's belongings from his room. During their heartfelt discussion, Min-chul inquired about the circumstances surrounding Bom's mother's demise, to which Ja-young responded softly, relating how her car had skidded on a wet road. Through their exchange, it became evident that Bom and Tae-yang's paths had crossed while both were pursuing studies abroad, with Bom's journey abruptly halted by the tragic loss of her mother.
Later, at the university, Cho Sang-heon made an imposing entrance into the principal's office, presenting a generous donation to the institution. With a hint of urgency, he petitioned the principal to award Bom a scholarship for overseas studies, urging for her swift departure.
Finally, Min-cheol confronted Bom upon their return from their journey, his tone tinged with resentment. He subtly accused her of diverting Tae-yang's focus from his academic pursuits and professional aspirations. With a stern request, he exhorted her to escort Tae-yang back home and to refrain from further entangling her life with his.
Bom subsequently sends a text to Tae-yang, requesting a private meeting. She discloses her encounter with his father and urges him to return home. She opens up about her heartache concerning her late mother, contrasting it with Tae-yang's fortune of having a father, albeit a nagging one. Meanwhile, Sa Gye catches sight of Bom ascending from the rooftop, his vision momentarily blurring with concern. Upon her arrival upstairs, his inquiries about Tae-yang swiftly reveal Bom's distress.
Elsewhere, Tae-yang reluctantly obeys and heads back to his family home. His father issues a stern command to steer clear of Bom and mandates his presence at a surgical procedure later that day.
Moments later, the principal informs Bom of a prestigious scholarship bestowed upon her. However, proud and reluctant to accept charity, she declines the offer.
Tae-yang indeed attends the surgical procedure arranged by his father but is overwhelmed by the sight of blood, triggering haunting flashbacks to a young Tae-yang returning home to the devastating discovery of his mother's suicide. Struggling to breathe, Tae-yang flees the scene. Min-cheol catches up to him, striking him in frustration, ashamed to have a son of such fragility.
Determined to sever ties with his medical aspirations for good, Tae-yang reaches for a shard of glass, intending to maim his own hands. Min-cheol stands aghast, but it is Sa Gye who intervenes, having visited the building for an eye examination. He also reveals having overheard Min-cheol's conversation with Bom at the restaurant. Min-cheol is summoned back into surgery, and before departing, Sa Gye imparts a poignant message to Tae-yang: by forsaking the life he truly desires, it is Tae-yang alone who suffers the loss.
Despite his recent disagreement with his father, Tae-yang eventually arrives for band practice, determination etched across his face. The ensemble dives into the creation of their new song for the school festival, and under Bom's astute guidance, their music blossoms over the subsequent days.
One fateful night, Bom succumbs to exhaustion, drifting off in the band room, while Sa Gye remains, his thoughts a tumult. Awakening abruptly at 3 am, Bom panics to find the university gates securely shut, trapping them within. Faced with no alternative, they reluctantly decide to stay put.
In the quiet of the night, Bom confronts Sa Gye, reminding him that he still hasn't apologized for his drunken embrace. He stands firm, asserting that his hug stemmed from genuine affection, not alcohol-fueled impulsiveness. Suddenly, the lights flicker and plunge into darkness, leaving Bom terrified by the encroaching shadows. Instinctively, she seeks refuge in Sa Gye's arms, her fear of the dark overcoming her.
Amidst the soft glow of moonlight seeping through a window, Bom confides in Sa Gye her heartfelt wish – she dreams of managing him as an artist,复兴his career, and proving to the world that he is still the extraordinary Sa Gye. He, however, gently reminds her that a manager typically needs to offer an artist an advance to secure their signing. With a mixture of hope and daring, Bom urges Sa Gye to sign first, pledging her commitment. He, touched by her sincerity, agrees.
As the episode of "Spring of Youth" reaches its climax, Sa Gye leans in, his intentions clear, and kisses Bom, sealing their mutual understanding and aspirations in a tender moment that marks the end of Episode 3.
