My Only One

When Kang Su-il is sentenced to prison, Kim Dong-cheol offers to raise his infant daughter as his own. Nearly three decades later, Su-il walks free.

For her sister, Kim Do-ran offers to give up her life savings to So Yang-ja. Dong-cheol bumps into someone he must avoid at all costs.

When photos from his missing USB drive are leaked online, Wang Dae-ryuk suspects Do-ran. Su-il starts working for the Wang household.

At a job interview, Do-ran has another unpleasant run-in with Dae-ryuk. Oh Eun-yeong opposes her son's marriage to Na Hong-sil's daughter.

On her way to the final round of her job interview, Do-ran gets held up on the street by an older woman who seems to think she's someone else.

Meeting Do-ran as the Wang family's chauffeur, Su-il embraces the opportunity to speak to her. Dae-ryuk keeps up what he sees as a harmless joke.

Jang Da-ya digs up information on her father's murder case. Su-il resolves to stay. Dae-ryuk tries to apologize to Do-ran.

Dae-ryuk and Do-ran do their best playing games at the company retreat. After Da-ya and Wang I-ryuk's wedding, Park Geum-byeong goes missing.

When Do-ran's threatened over her mother's debt, Su-il pledges to take care of it himself. Worried about Do-ran, Dae-ryuk goes to her house.

Upset about her mother and sister, Do-ran opens up to Su-il. Later, she heads back to the Wang residence to calm down Park Geum-byeong.

Do-ran considers an unusual request from Eun-yeong. In an attempt to quash his feelings for Do-ran, Dae-ryuk tries dating another woman.

Do-ran, Su-il and Dae-ryuk wind up going to an amusement park with Geum-byeong. Yang-ja gets the wrong impression of Su-il.

Su-il's refusal to help him win over Do-ran disappoints Dae-ryuk. Inside the Wang residence, Do-ran runs into trouble with Da-ya.

Following the competition, Do-ran is placed on Dae-ryuk's team. Da-ya is ordered to apologize. Na Hong-ju meets Su-il at church.

Now that Geum-byeong has a caretaker, Da-ya wants Do-ran to stop coming around. Do-ran and Dae-ryuk officially go on a date.

Concerned about his mother, Wang Jin-kuk requests Do-ran be brought back. Kim Mi-ran suffers a blow to her ego at a get-together with friends.

Hong-ju's heart is stolen when Su-il chases down a pickpocket for her. Su-il decides to support Dae-ryuk in his pursuit of Do-ran.

Hong-sil panics when she realizes Su-il is the man her sister has fallen for. Da-ya's jealousy grows when she sees Do-ran's new necklace.

Da-ya finds out about Do-ran and Dae-ryuk's relationship. Meanwhile, Dae-ryuk tells Do-ran he wants to take things to the next level.

Eun-yeong wants Do-ran to end everything and get as far away as possible from her son. Hurt, Do-ran comes to a heartbreaking decision.

Dae-ryuk learns the real reason behind Do-ran's actions. Eun-yeong and Da-ya attempt to give Geum-byeong a convincing stand-in for Do-ran.

Dae-ryuk faces off against his mother, who is adamant that he cannot marry Do-ran. Meanwhile, Jin-kuk says he approves of their union.

Do-ran's background as an orphan becomes an obstacle for her marriage. Geum-byeong sets out to make sure Do-ran and Dae-ryuk can remain together.

At the wedding, Su-il is spotted by someone who knows his true identity. Da-ya discovers an interesting document in Geum-byeong's room.

A household staff finds Do-ran's photo inside Su-il's room. Mi-ran heads to a blind date, all the while moping over Jang Go-rae.

Do-ran is stunned to hear her biological father was present at her wedding — doubly so when Geum-ok points him out in a photo.

Learning Do-ran knows his identity, Su-il packs up to disappear. Eun-yeong is determined to make Do-ran's married life tough.

Geum-byeong and Su-il lend a hand when Do-ran's handed a ton of housework. Geum-byeong wanders to Do-ran's old house again.

Yang-ja shows up at the Wang residence to ask for money, vexing Eun-yeong. Mi-ran decides she wants to be with Go-rae.

Go-rae brings Mi-ran home to his mother and aunt, introducing her as his intended. Needing funds for the marriage, Yang-ja goes to Dae-ryuk.

When Go-rae refuses to give up his engagement, Da-ya tries to talk him out of it. Geum-byeong's jewelry goes missing, and Do-ran becomes a suspect.

Da-ya reports to Eun-yeong that she saw Do-ran visiting Su-il's room late at night, and grows increasingly resentful as her claims are dismissed.

The Wang family doesn't understand why Su-il wants to quit all of a sudden. Da-ya gets her hands on shocking DNA test results.

Insisting Su-il return to his job, Geum-byeong says she'll go on a hunger strike. Dae-ryuk follows Do-ran as she goes somewhere one night.

The unveiled secret about Do-ran and Su-il astounds Eun-yeong, who kicks Do-ran out of the house. Out on the street, Do-ran collapses.

Eun-yeong is thrown off guard when an attorney shows up with divorce papers. Hearing this, Do-ran rushes back to the house.

When a former fellow inmate of Su-il's reappears in his life, Do-ran wonders how they know each other. Hong-sil gives Mi-ran the cold shoulder.

After witnessing Su-il and Hong-ju together, Da-ya throws a fit in front of Do-ran. Yang-ja has a bone to pick with Hong-sil.

Reading letters written to her father, Do-ran learns what he's been hiding from her all along — as well as the crimes of his past.

Requesting divorce from Dae-ryuk, Do-ran takes her belongings out of the house. Yang-ja thinks she's the reason behind their separation.

Despite the truth about Do-ran's father, Dae-ryuk wants to stay together. Knowing that his past has hurt his daughter agonizes Su-il.

Finding out that Su-il was once incarcerated throws Hong-ju into a state of shock. Go-rae reveals to Mi-ran that his father was murdered.

When a horrified Hong-sil and Da-ya show up, Hong-ju tells them she wants to spend the rest of her life with Su-il.

Having uncovered the awful connection between Su-il and her father's death, Da-ya interrupts her aunt's wedding. Hong-sil is inconsolable.

Da-ya announces to the neighborhood that Su-il's bakery is run by a murderer. Jang So-yeong comes across Dae-ryuk at a bar.

Su-il asks around about a man who may be able to fill in a gap in his memories. Hong-sil comes by the bakery and causes a scene.

As Geum-byeong's condition worsens, a desperate Jin-kuk turns to Do-ran. Go-rae speaks to Su-il about his father's death.

While Dae-ryuk sets his sights on reuniting with Do-ran, Eun-yeong has other ideas. Go-rae deals with difficult news.

Hong-sil declines Su-il's offer to save her son's life, but with Go-rae's health deteriorating fast, Mi-ran urges her to reconsider.

With Su-il stuck in a coma, Dae-ryuk sticks by Do-ran's side against his mother's wishes. A mysterious man has something he needs to say to Su-il.

Hoping for answers, Do-ran and Dae-ryuk track down the mysterious man. While in Su-il's hospital room, Eun-yeong gives Do-ran a harsh warning.

Apologies are made. Su-il opposes Do-ran's return to the Wang family, afraid she will be treated with disrespect.

Dae-ryuk faces competition for Do-ran's affections. Da-ya gets unexpected help as she confronts her husband. Eun-yeong regrets her actions.