Who Is She - Season 1

Mal-soon, now in her seventies, has spent her life guiding her daughter toward a successful career, fully aware that her efforts might earn her resentment. Though her daughter now enjoys a stable and accomplished life, the emotional distance between them has grown insurmountable over the years. After a heated exchange of painful words, Mal-soon steps out the door, feeling hollow and adrift, unaware of the unexpected turn her life is about to take.

Mal-soon can't believe she is inside someone else's body and doesn't know what to do. While the people who know her question her whereabouts, she wanders, figuring out what to do, and then stumbles across the Royal Salon, a place of memories from 50 years ago. Meanwhile, Daniel Han of UNIS Entertainment tracks down Emily, the girl Mal-soon looks just like.

Oh Mal-soon, no Oh Du-ri begins her new life as a trainee in UNIS Entertainment! Meanwhile, Ji-sook receives a call from her aunt and realizes her father is actually alive. Without a clue, Du-ri focuses on her training to be a singer. While she takes steps to get close to her dream, she's shocked to realize that UNIS Entertainment belongs to Ae-sim.

Du-ri realizes her success is the biggest revenge on Ae-sim and decides to debut. However, she sees Min-seok getting out of a strange woman's car and Ji-sook leaving the real estate. She has no idea what's been going on in her town while she was gone, and decides to find out. Du-ri reveals herself to her old friend Mr. Park and asks him for help to check what's on her family's mind. Then, she meets a woman who looks just like her. Who on earth is she?

Du-ri, Ji-sook, Min-seok, and Janet meet each other. Janet, the woman who looked just like Mal-soon, is actually Mal-soon's younger sister Kkeut-soon. Janet plans to approach Mal-soon's family, but Mal-soon has already erased her from her life. Meanwhile, Ha-n Na joins the debut group and works hard with Du-ri not to be crowded out. However, Ae-sim instinctively raises her guard against Du-ri. Ae-sim finds Du-ri an eyesore, and she even gets a suspicious report about her private life.

Du-ri gets another chance when the video of her at a song festival goes viral. Meanwhile, Ji-sook feels more disturbed by day because of her father and the competition at her company, but Min-seok, who is clueless, is upset about her cold attitude. Janet eventually enters Mal-soon's house, and Daniel becomes a guest at Park's Guesthouse. Watching Daniel and Du-ri get closer, Park feels left out. He goes missing and Du-ri starts to worry when a strange man appears in front of her. Who is he?

The young man who saves Du-ri is Park. Park also became young thanks to the Youth Photo Studio. Mr. Park or his new name Park Jun moves into the guest house and starts tension with Daniel over Du-ri. Meanwhile, Janet assures Mal-sun that Mal-sun will need her help, so Du-ri leaves her life to Janet and focuses on her debut. Du-ri chasing after her dream reminds Ae-sim of Mal-sun in the past.

Janet and Mal-sun look the same, but they have nothing in common. Whereas Du-ri resembles Mal-sun a lot as if she's possessed by Mal-sun. Ji-sook's suspicion about the two grows. Meanwhile, Min-seok is shocked to hear about Ji-sook's father after following her to the hospital. On the other hand, Ae-sim wants to get rid of Du-ri out of her sight. Thanks to a text from an anonymous number, she realizes Daniel and Du-ri close relationship and becomes furious.

Daniel is firm despite what Ae-sim says. He threatens Ae-sim to leave if she kicks Du-ri out, and Du-ri's heart races to see that. When Ae-sim backs down, a dark shadow draws on her. Meanwhile, both Janet and Du-ri fill in for Mal-sun's gap in their own ways. Du-ri invites Ji-sook to UNIS. Including Ha-na, the three of them have a good time after a while. At that moment, Ji-sook receives a call from Min-seok.

Mal-sun's old secret is unveiled when Ji-sook's father dies. Ji-sook realizes there was a misunderstanding between her and Mal-sun. She's finally ready to rely on her mom, but Janet disappears. Meanwhile, Ae-sim was looking for a way to expel Du-ri. Then she takes Ji-an's advice and leaks Du-ri and Park-jun's scandal. Yet, Daniel's feelings for Du-ri don't change. When the two realize their feelings for each other, they go on a secret trip together.

Daniel holds a press conference and reveals that Yoo Ji An was the one who manipulated Doo Ri's dating scandals and that she was his stalker, not a girlfriend. Ji An threatens Ae Shim that she'd reveal Daniel and her secret if the matter isn't taken care of. Meanwhile, Mal Sun realises that her body is getting old and fears that she might return to her old self.

Mal Sun has to choose between returning to her old self or living as Doo Ri but disappearing after six months. Her twin sister Kkeut Sun comes back to her, and Mal Sun realises that she was in fact Emily. Mal Sun contemplates before making her final decision as she can't imagine not being able to live as Ji Suk's mother. Right then, Ji Suk tells her something that helps her make a decision.