Episode 3 of Spring of Youth intensifies the emotional tension as Spring of Youth Episode 3 kicks off with a drunken Sa Gye hugging Kim Bom. Tae-yang witnesses this and furiously shoves Sa Gye aside before hauling his unconscious rival away. The next morning, an oblivious Sa Gye gets a warning from Tae-yang to never act that way toward Bom again. Shortly after, Sa Gye confronts Kang Seok-hee about spying on him. Seok-hee warns him to stay away from both the school and Bom if he doesn’t want her to get hurt. Ignoring this, Sa Gye texts CEO Cho Sang-heon to back off and starts tailing Bom—even sitting through her music class before dozing off. When class ends, Bom argues with him and ditches him stealthily.

A deadly past and dangerous secrets emerge

Elsewhere, CEO Cho meets Tae-yang’s father, Seo Min-cheol, to revisit a buried tragedy. A flashback reveals Cho caused a fatal car accident six years ago while driving drunk—with Min-cheol as a passenger. Rather than helping the woman in the other car—Bom’s mother—they both fled the scene. In the present, Cho reveals Sa Gye may have seen the accident and shocks Min-cheol by revealing that Bom was the victim’s daughter. Learning that Tae-yang, Bom, and Sa Gye are now living together only adds to Min-cheol’s horror.

Back at school, Sa Gye shares exciting news—their band will perform first at the school festival. But conflict brews quickly as he and Tae-yang fight over the roles of leader and lead guitarist. To cool tensions, Bom suggests a group trip. Cho Ji-na brings a van, and the crew convinces her to come along. At the campsite, Sa Gye’s constant shadowing of Bom infuriates Tae-yang, and another fight causes Bom to fall into the river. Tae-yang pulls her out while Sa Gye, trying to help, knocks himself unconscious on a rock.

Unintentional kisses and revelations

As Tae-yang attempts CPR, a dazed Sa Gye springs up and accidentally kisses Tae-yang by falling over him. After some awkwardness, both boys agree to put aside their rivalry. Bom, pretending to be sick, assigns roles: Sa Gye as lead guitarist, Tae-yang to choose their song, and takes leadership herself. Gyu-ri arrives and exposes that Bom can actually swim, proving she faked her condition to unite the boys.

That evening, Ji-na finds a new song in Bom’s notebook but hides it when Bom enters. The next day, Min-cheol visits Bom’s guardian, Kim Ja-young, to collect Tae-yang’s belongings. Their conversation reveals that Bom and Tae-yang met while studying abroad—Bom returned after her mother’s death. Meanwhile, Cho meets the university principal and offers a large donation in exchange for Bom receiving a scholarship to study abroad—essentially sending her away.

Emotional confessions and harsh choices

After the trip, Min-cheol meets Bom and subtly accuses her of distracting Tae-yang from his future. He insists she let Tae-yang go. Bom agrees and texts Tae-yang to meet. She tells him to return home and expresses grief over her mother, pointing out that he’s lucky to have a nagging father. Sa Gye, watching from the rooftop, notices her upset demeanor afterward.

Tae-yang reluctantly returns home. His father demands he avoid Bom and attend surgery training. Later, Bom is offered the special scholarship but refuses, not wanting pity.

Tae-yang’s breakdown and Sa Gye’s intervention

During surgery, Tae-yang experiences panic at the sight of blood. Flashbacks of his mother’s suicide overwhelm him and he flees. Min-cheol berates him as a weak son. Desperate, Tae-yang tries to injure his hands with glass to quit medicine for good. Sa Gye, at the hospital for an eye exam, stops him just in time. He also reveals he overheard Min-cheol’s conversation with Bom. Before returning to the operating room, Min-cheol hears Sa Gye’s parting words—if Tae-yang doesn’t live his own life, he’s the only one losing.

Tae-yang rejoins the band, and under Bom’s leadership, they begin rehearsing seriously for the festival.

Romantic shift and emotional closure

One night, Bom falls asleep in the band room and ends up locked in with Sa Gye. At 3 a.m., they realize they’re stuck. She confronts him about hugging her while drunk, but Sa Gye confesses he did it because he likes her. When the lights go out, Bom hugs him in fear. In the moonlight, she tells him her dream—to manage him and reintroduce him to the world. Sa Gye jokes that managers have to pay their artists, but Bom tells him to sign first. He agrees, and they share a kiss to close Spring of Youth Episode 3.