Young-eun is working hard to win a contract with a famous fashion designer’s brand. However, things aren’t working out as planned, and now she should go on a blind date in place of her friend Chi-sook. There, she gets to meet a guy named Jae-guk, a photographer. At first, she doesn’t even bother to show the slightest interest in him because she’s preoccupied with her work. But she soon realizes that she needs his help.

The One’s 30th anniversary event is only a few days away. To make the event a success, Young-eun and her team members work hard and try to invite Hye-rin, a popular influencer, as the model of their new clothes. However, things aren’t going well as Hye-rin is being very picky and uncooperative. Only one day is left until the event, and Young-eun comes to make a big decision. Meanwhile, Jae-guk finds out who bought his photo in Paris ten years ago.

Young-eun wants to know about the relationship between Jae-guk and Soo-wan. She shares with Jae-guk her memories of how she first met and broke up with Soo-wan. She soon hears about the news of Soo-wan from Jae-guk. Meanwhile, everyone at The One is shocked by the news that the main design of Sono’s new collection has been copied, and is already on sale in the market.

Young-eun lives in grief and remorse after finding out the fact that Soo-wan died on his way to meet her ten years ago. On top of it, due to the decline in sales of Sono, Young-eun gets transferred to a team that deals with a new licensing brand. Chi-hyung, Chi-sook’s younger brother, comes back from studying abroad and joins Young-eun’s team. Meanwhile, Chi-sook starts to think that Do-hoon has a crush on Young-eun.

Young-eun gets extremely busy finding new factories her team can work with. Then, she hears that her father is in the police station. When she gets to the station, she becomes surprised to see a man who is sitting next to her father. Meanwhile, Chi-hyung finds out that another team at The One is trying to have Sono’s team member leak Young-eun’s business plan in exchange for offering her a better position.

Young-eun decides to stop pushing Jae-guk away, and he becomes a great help in promoting Sono’s new collection. Mi-sook wishes that she was misdiagnosed earlier and goes to see the doctor again. Chi-sook, who thought she had found out about Do-hoon’s secret, gets to realize that she’s been mistaken. Meanwhile, Yoo-jung recollects her memories of how she tried to separate Soo-wan and Young-eun ten years ago.

Do-hoon starts to act strange when Chi-sook is around him or when she sends text messages to him. Chi-sook wants to know why and decides to ask Do-hoon herself. Mi-sook withdraws all the money from her bank accounts and starts to buy whatever she wants to have just for her and her mother. Meanwhile, Young-eun gets to find out the fact that Soo-wan and Yoo-jung were engaged even when Soo-wan was seeing Young-eun.

Jae-guk receives offers from several global brands, and he decides to work with a Parisian company called DPHP. Meanwhile, Young-eun’s team is shaken up when Hills Department Store calls and says they want to cancel the deal with Sono. As Young-eun tries to make things work out with President Choi of Hills, Mi-sook calls Young-eun with an emergency.

Soo-ho quits working to look after Mi-sook. However, Min-kyung, with whom Soo-ho has secretly been having an affair, comes to Soo-ho and Mi-sook’s place unannounced. Chi-sook also finds out that Mi-sook is ill and starts to persuade Mi-sook to get hospitalized and receive treatment. Unexpectedly, Jae-guk’s mother tells Jae-guk that she wants to cook a meal for Young-eun. Without knowing that she had an ulterior motive, Jae-guk invites Young-eun with joy.

Young-eun’s mother finds out that Soo-wan died ten years ago and that Jae-guk was born out of wedlock. She starts trying to strongly stop Young-eun from seeing Jae-guk. She even barges into Jae-guk’s photo studio and causes a scene. Young-eun waits for Jae-guk’s call, but she doesn’t get any from him. Meanwhile, Chi-sook starts to feel confused with Do-hoon after seeing his new style and hearing something surprising from him.

Young-eun is extremely busy and tired of working with Sono’s new partner company because they keep asking for unreasonable demands and being very fickle-minded. Meanwhile, Chi-sook accidentally hears the secret conversation between Soo-ho and Min-kyung and learns that Soo-ho is cheating on Mi-sook. Feeling upset and betrayed, she goes straight to Mi-sook’s place to share what she found out.

Everyone working for The One hears a rumour that the company might be sold off. Although most of the employees are tormented by the sense of insecurity and anxiety, Young-eun decides to continue to work on the project she’s been working on. She plans to hold an online fashion show and send out invitations to globally influential buyers. She also asks someone who always wanted to be a fashion model to be a model for her show.

Sono gets an offer from Olivier and Nouvelle Vague meets Young-eun saying they want to do an interview. At first Young-eun agrees, but when she sees the questions, she refuses saying that none of the questions are about Sono. Mi-sook prepares to say goodbye by making kimchi with her friends and sharing it with them. Meanwhile, Jae-guk tells Young-eun he’s planning to go to Paris.

After much consideration, Young-eun turns down the offer from Olivier. Instead, President Hwang offers Young-eun to start a separate business with Sono and gives her time to think about it. Meanwhile, Jae-guk starts getting ready to go to Paris and buys two tickets. He then asks Young-eun to come with him.

As Mi-sook’s disease spreads, she prepares to say goodbye to her friends and family. Chi-sook’s misunderstanding against Do-hoon is resolved when she hears from her father that the reason he hired Do-hoon wasn’t her. After contemplating, Young-eun decides to quit Sono and start her own brand.

After Young-eun quits Sono, she starts her own brand, but it’s proving more difficult than she thought. Do-hoon and Chi-sook start to live together and Chi-sook helps Young-eun start her own brand. Jae-guk comes back from Paris for a fashion show in Busan and meets Young-eun.