Go Yeong-rye hustles through her hectic days as a bus conductor. At work, she crosses paths with the sharp-tongued Seo Jong-hee, forming an unlikely bond. When Yeong-rye is in trouble, Han Jae-pil rescues her from a dangerous situation. When the fellow conductors try to give Jong-hee a hard time, Yeong-rye steps in to help, and their friendship grows.

Determined to change her life, Go Yeong-rye searches tirelessly for the mysterious Giant, only to end up in trouble at a nightclub. Meanwhile, Han Jae-pil negotiates with his father, gaining permission to continue boxing in exchange for studying under the elite tutor, Go Yeong-sik. With Seo Jong-hee, Go Yeong-rye enrols in a night school.

Go Yeong-rye and Seo Jong-hee go on a group date, where Yeong-rye unexpectedly meets Han Jae-pil. The group heads to a roller-skating rink, and Sang-cheol invites Yeong-rye and Jong-hee to watch a boxing match. As Jong-hee watches Jae-pil fight, she is shaken when memories of past violence resurface. Overcome by her trauma, she abruptly stops the match.

After her mother’s sudden surgery, Yeong-rye takes a few days off work with the help of her coworkers. Yeong-bae and Yeong-mi visit Sae-ri’s house. Jae-pil, who has feelings for Jong-hee, grows closer to her, and Jong-hee begins to see his vulnerable side. When Yeong-rye notices their bond deepening, her own feelings become conflicted.

Jae-pil and Sang-cheol discover that Yeong-rye and Jong-hee are not university students, but bus conductors who attend Hwarang Night School. Feeling ashamed after being found out, Jong-hee begins to distance herself from Jae-pil. Jong-nam tracks down Jong-hee and causes a scene at Cheongah Bus, forcing Jong-hee to go into hiding.

When Cheongah Bus refuses to compensate for a serious accident that leaves a conductor severely injured, the conductors organise a strike. Yeong-rye seeks advice from Hyeon and Yeong-sik about the strike. Meanwhile, Jong-hee learns of Yeong-rye’s feelings for Jae-pil and makes up her mind. When Yeong-rye finds herself in danger, Jong-hee steps in to help, putting herself at risk.

Yeong-rye and Jae-pil’s feelings for each other continue to deepen, but they both try to stay within the boundaries of friendship. Jae-pil is consumed by his hectic life at the hospital, while Yeong-rye balances her work at the salon with caring for her family. When Jeong Hyeon, who left seven years ago, suddenly returns, Jae-pil finds himself overcome with jealousy.

Jong-hee and Yeong-rye unexpectedly reunite at Juri Beauty Salon. Jong-hee tells her story of how she was adopted by a chairwoman, and with this encounter, she finally catches up with everyone she used to know back when she was a bus conductor. However, things become complicated as she sees how close Yeong-rye and Jae-pil have gotten during her absence.

Jong-hee gets hospitalised, and she meets Jae-pil as her doctor. They talk about their time together back in the day, and Jong-hee’s heart starts to grow again. Mi-suk doesn’t want Jong-hee to get along with her friends from the past, and this becomes an argument between her and Jong-hee. Meanwhile, Jong-hee takes Yeong-rye to Hwaran School and talks about their old days.

Yeong-rye gets a new job at a different beauty salon. She attends the beauty seminar on her first day, and something she’d never expected happens. Jong-hee discovers that Mi-suk caused Yeong-rye to lose her job. Hyeon confesses his feelings to Yeong-rye, and Yeong-rye feels sorry and thankful at the same time. Meanwhile, Jae-pil confronts his feelings toward Yeong-rye.

Director Michelle suggests that Yeong-rye enter the Miss Korea pageant. Yeong-rye has a lot of concerns, but thanks to her family and friends’ support, she decides to join the pageant. Hearing the news, Jong-hee also decides to join the pageant. Meanwhile, Sang-sik finds out that Jong-hee was one of the Miss Korea contestants.

Jong-hee is worried after seeing Sang-sik at the pageant. After hearing about this, Mi-suk decides to take care of Sang-sik in her own way. Finally, it’s the final day of the Miss Korea pageant, and everyone is gathered at the cultural center. Meanwhile, Sang-sik gets away from Mi-suk’s scheme, and he plans to hurt Jong-hee. The winner of the 1989 Miss Korea is finally announced.