18 Again

Dae Young, facing a pivotal basketball game and the possibility of divorce after 18 years of marriage, finds himself given a second chance when he mysteriously wakes up with the body of an 18-year-old.

Ko Woo Young, living as 18-year-old Hong Dae Young, begins to understand the life his children are leading and chooses to support them as a friend. Meanwhile, Da Jung undergoes a blind recruitment process at JBC and runs into an old high school acquaintance, Choi Il Gwon, during a night out with Ae Rin. On their way home, Da Jung encounters Woo Young, whose appearance seems to merge with that of Dae Young.

Da Jung receives news about the outcome of a public recruitment through a call from JBC, while Woo Young confronts Ja Sung over his continued harassment of Si Woo. On her first day at JBC, Da Jung faces prejudice due to her marital status, but is unexpectedly given a last-minute opportunity to conduct an interview just before going live.

During a team dinner, Ji Hoon asks the director to assign Da Jung to his upcoming interview. At the same time, Si Ah is hospitalized, causing concern, particularly for Woo Young. Da Jung is disappointed by Dae Young's indifferent reaction to Si Ah's situation and is upset that he is deceiving her about a business trip to Busan.

Dae Young, in the guise of Woo Young, tries to understand Da Jung's reasons for wanting a divorce but fails to get a clear answer. He later discovers that Il Gwon is seeing his first love, leading him to suspect an affair between Il Gwon and Da Jung. At the same time, Da Jung gains public attention after her interview video goes viral.

Dae Young is troubled by Ji Hoon's growing interest in Da Jung, especially as Da Jung's divorce becomes public and leads to the loss of her TV programs. Ji Hoon comforts Da Jung by taking her to the countryside, while Il Gwon decides to stop pursuing her. At the same time, Dae Young learns that his father has been secretly looking after his children and Da Jung.

Deok Jin expresses envy toward Dae Young's regained youth, and Woo Young inadvertently reveals his true identity in front of Ae Rin, who is waiting for Da Jung. At the same time, Il Gwon pressures Da Jung into an uncomfortable request in his role as Si Woo's basketball coach, and despite Woo Young's guidance, Da Jung's attempt to act responsibly leads to a confrontation with Il Gwon.

Woo Young becomes concerned that Da Jung may have discovered his secret after overhearing her conversation with Il Gwon, while Da Jung is stunned by revelations about Dae Young. Dae Young, seeking connection with his estranged father, invites him to a basketball game and later opens up emotionally.

Da Jung takes action against Il Gwon's questionable coaching methods with the help of other parents, and after obtaining evidence with Woo Young's assistance, they both reflect on the things they've taken for granted. As a result, Da Jung begins to feel a sense of comfort and security in Woo Young's supportive presence.

Woo Young saves a child from an oncoming car and is hospitalized, while Da Jung, encouraged by her family, agrees to appear on a reality show about divorce. As he recovers, Woo Young feels the emotional distance from his family and decides to return to Da Jung.

Woo Young silently leaves after seeing Da Jung smile with Ji Hoon. During the school festival, Ja Sung confesses to Si Ah, leading to unexpected chaos. Regretful over losing the women in his life, Woo Young hears a significant question from drunk Da Jung.

Da Jung is unsure whether her encounter with Woo Young was real or just a dream, and she avoids confronting him. As tensions between Woo Young and Ji Hoon escalate, the three reunite at the launch party for Go Go Play.

Woo Young unexpectedly kisses Da Jung, causing her to pull away, unsettled. Despite his attempt to explain, Da Jung ends the conversation. At the same time, she discovers that Si Ah's job at a convenience store is not just for extra income.

Da Jung becomes unsettled after hearing Woo Young's unexpected confession just before a major employment announcement. Regretting his outburst, Woo Young tries to make amends as Da Jung deals with the aftermath. Following the announcement, Ji Hoon reaches out to Da Jung's ex-husband during a tense situation.

Woo Young and Da Jung, who haven't had a proper date in a long time, decide to reconnect by going out together. At the same time, Woo Young receives a mysterious phone call asking for Dae Young, adding tension to his already complicated situation. Despite receiving a conditional offer from the Hanguk University basketball team alongside Si Woo, Woo Young begins to question whether his dream of becoming a professional basketball player is truly what he wants.

On her way to watch Si Woo play basketball, Da Jung encounters Woo Young and feels guilty for disrupting his life once more. At the same time, a video resurfaces that initially seems to threaten Da Jung's stability but instead brings her long-overdue recognition. Two years later, Dae Young proposes a fresh start to Da Jung.