Episode 5 of "Family By Choice" kicks off with a chillingly tense ambiance, setting the stage for a stressful dinner. Dae-wook is left astounded when Jung-hee makes an unexpected appearance, sparking a heated altercation between San-ha and Hae-joon. The boys find themselves in a futile competition to outdo each other, prompting Dae-wook to reprimand them for their deplorable table etiquette. In a huff, both San-ha and Hae-joon abandon their meals unfinished, earning Dae-wook a scolding from Jung-jae for causing the kids to leave.
A week passes, and Joo-won confides in Dal about the oppressive dinners at home, marred by the ongoing rift between San-ha and Hae-joon. Dal advises patience, suggesting that the boys need time to mend their fences. Determined, Joo-won vows to reconcile Hae-joon and San-ha by the time Hae-joon's birthday rolls around, an occasion also marked by the visits of his aunt.
Meanwhile, Joon-ho reaches out to Joo-won, inviting her on a date. This unexpected turn gives Joo-won an ingenious idea. She calls both Hae-joon and San-ha for a bike ride date, accompanied by her. Though initially resistant, the boys unwittingly fall into Joo-won's clever plan. Joo-won enlists Dal's help, hoping the outing will foster camaraderie among the trio.
On that Sunday, Dal fibs to her mother about attending an academy session, instead sneaking off for the bike ride with Hae-joon and San-ha. Joo-won is taken aback to discover half her school has joined the impromptu biking event. The boys' surprise deepens when Joon-ho attempts to join Joo-won on her bike.
Dal's tardiness leads her to the park, where she encounters a group of boys. Desperately trying to reach Joo-won, still on her bike, Dal finds herself in a pickle. Hae-joon extends an apology to San-ha for punching him, but San-ha demands an apology for past grievances, escalating their spat further and leaving Joo-won distressed.
Driven by frustration, Joo-won pedals faster, eventually dismounting to search for Dal. She spots Dal being pestered by the group and, despite her exhaustion, rushes to her rescue. Joo-won collapses from fatigue, prompting the boys to rush to her side with water.
Hae-joon and San-ha are utterly astonished to find Joo-won in such a condition. Convinced that the boys had somehow harmed Joo-won, the duo retaliates with fists flying. San-ha attempts to intervene, shielding Hae-joon as they lay waste to their targets. That fateful night, the trio finds themselves entangled in the web of law enforcement, ending up at the police station.
Elsewhere, at the restaurant, Jung-jae poses a question to Dae-wook, suggesting they trim their expenses to acquire a second-hand car for San-ha and Hae-joon before their college journey begins. Just then, Dae-wook receives an urgent call from the station informing him of the boys' arrest for instigating a brawl. Without delay, he rushes to their aid.
In the meantime, San-ha offers heartfelt apologies to the boys they assaulted, acknowledging his haste in acting without the full picture. Dae-wook, arriving on the scene, urges the officers to mete out harsh punishment to San-ha and Hae-joon, but the victims, surprisingly, opt for leniency.
Outside, Joo-won endeavors to clarify the situation, explaining how the boys had actually tried to assist her. Dae-wook, in the midst of this turmoil, decides to drop Dal off on his way back home. Worried sick, Dal's mother spots her daughter outside the academy and scolds her for ignoring her calls. Dal fabricates a tale, claiming she was studying with Joo-won's elder brother, San-ha, who was aiding her in preparation for an impending mock exam.
Inside, the boys gently lay Joo-won to bed and stage a reconciliation in her presence. However, outside her room, Hae-joon and San-ha find themselves locked in another heated dispute, ultimately agreeing to maintain their charade in front of Joo-won during their school walk the next day.
Joo-won expresses relief to Dal, stating how glad she is that San-ha and Hae-joon have seemingly returned to their usual selves. That same day, a gossip ripples through the school, whispering tales of Dal's burgeoning affection for Hae-joon. Hui-ju confronts Hae-joon directly, inquiring about his feelings for Dal. Hae-joon dismisses Hui-ju's accusation, asserting that Dal is like a sister to him, solely because she is friends with Joo-won.
Joo-wonforcefully pulls Dal along, urging her to confess her affections for Hae-joon, unaware that Dal, eavesdropping, is left utterly devastated. In a fit of anger, Joo-won kicks Hae-joon and attempts to comfort Dal, who is now in turmoil. During class, Dal publicly dismisses any notions of romancing Hae-joon to quell the burgeoning rumors.
Post-school, Joo-won and San-ha venture to a mall to celebrate Hae-joon's birthday. Joo-won confides in San-ha about Dal's heartbreak, but he cautions her to stay out of their emotional entanglements. Together, they pick out basketball shoes for Hae-joon, and San-ha impulsively decides to get Joo-won a pair as well. Mistaking them for a couple, the cashier offers a sweetheart discount. San-ha starts to clarify, but Joo-won silences him, playfully pretending to be his girlfriend to secure the deal.
Meanwhile, Jung-hee and So-hee dine at a restaurant within the mall, where So-hee insists on meeting San-ha. When Jung-hee steps away to the restroom, So-hee catches sight of San-ha and Joo-won. Frightened, she bolts after San-ha, ultimately tripping and injuring herself. San-ha rushes to her aid, while Jung-hee frantically searches for So-hee, eventually reuniting them with a relieved sigh. Jung-hee complains that wherever San-ha goes, trouble follows, but this remark irks Joo-won, who defends San-ha passionately, insisting that his presence brings joy.
On their way back, Joo-won pauses, captivated by a street performer's melody. San-ha reflects on Joo-won's unwavering support since childhood, gazing at her with warmth. The following day, Hae-joon prepares for his birthday dinner, anticipating the arrival of his aunt, Yi-hyun. Jung-jae entrusts Joo-won with the task of waking San-ha. She enters his room as he dresses, but San-ha promptly asks her to knock, respecting their personal spaces. Noticing Joo-won's troubled expression, he wonders about her distress. Around his aunt, Joo-won feigns cheerfulness, while San-ha advises her to avoid mentioning sensitive topics to Aunt Yi-hyun.
Upon her arrival, Hae-joonconfides in his aunt, assurance radiating from his voice as he vows to strive his utmost and behave impeccably. Yi-hyun suggests to Hae-joon that perhaps he should contemplate accompanying his biological father to the USA, noting that they already owe Jung-jae an immense debt of gratitude. However, Jung-jae, unfortunately eavesdropping on the conversation, finds himself deeply distressed.
As dusk descends, Hae-joon slices into his cake amidst San-ha and Joo-won presenting him with a thoughtful gift. Dae-wook playsfully remarks that the traditional wisdom dictates receiving shoes as a gift often prompts recipients to depart swiftly. Yi-hyun counters by asserting that Hae-joon can't possibly abandon them, emphasizing the debt of gratitude he owes Jung-jae for nurturing him. This statement casts a gloom over the festive ambiance, ultimately leading Jung-jae to drown his sorrows in alcohol.
Jung-jae confides in Yi-hyun, recounting Hae-joon's endless efforts to assist him and breaks down in emotion. Yi-hyun, regretful for creating a scene, seeks forgiveness while Hae-joon and Joo-won gently escort Jung-jae to his rest. Outdoors, San-ha initiates the cleaning of the table, with Yi-hyun attempting to intercept him, insisting that his circumstances differ from Hae-joon's, as his father is compensating Jung-jae.
San-ha rises to Hae-joon's defense, filling Joo-won with pride and Hae-joon with a tender heart. Hae-joon, with compassionate intentions, walks Yi-hyun to a taxi stand. Yi-hyun apologizes to Hae-joon, urging him to leave his mother's memory behind and move forward. She underscores that Jung-jae has been the parental figure that his mother could never aspire to be.
Later that night, Hae-joon places hangover medicine in Jung-jae's room and apologizes on behalf of his aunt. He ventures to the rooftop, where Joo-won and San-ha eagerly await. Hae-joon expresses his gratitude to San-ha, leading to a heartfelt reconciliation between the two. The subsequent morning, Seo-hyun arrives at the restaurant to meet Jung-jae, bringing the episode to a close amidst intriguing anticipation.
