Main •
Song Hye-kyo as Ha Yeong-eun :38 years old, daughter of Kang Jung-ja and Ha Taek-soo, and a close friend of Hwang Chi-sook and Jeon Mi-sook, design team leader of a fashion company called 'The One'. She falls in love with Yoon Jae-gook •
Jang Ki-yong as Yoon Jae-gook and Mr. J :32 years old, freelance fashion photographer •
Choi Hee-seo as Hwang Chi-sook :38 years old, design director of 'The One', the daughter of CEO Hwang, a high school classmate of Ha Young-eun and Jeon Mi-sook, and Hwang Chi-hyung's older sister. She falls in love with Seok Do-hoon •
Kim Joo-hun as Seok Do-hoon :40 years old, representative of the talented PR company at the center of the trend. •
Park Hyo-joo as Jeon Mi-sook :38 years old, Hwang Chi-sook and Ha Yeong-eun's high school classmate, and Kwak Soo-ho's wife. She gave up her career as a model to marry Kwak Soo-ho. •
Yoon Na-moo as Kwak Soo-ho :36 years old, deputy head of the planning team. Jeon Mi-sook's husband and Seok Do-hoon's colleague.
Supporting People around 'The One' •
Joo Jin-mo as Representative Hwang :68 years old, Hwang Chi-sook's and Hwang Chi-hyung's father, CEO of 'The One', and a self-made man. •
Oh Se-hun as Hwang Chi-hyung :32 years old, new designer of 'The One' in the design team. He's the son of CEO Hwang and Hwang Chi-sook's younger brother. •
Jang Hyuk-jin as Go Gwang-soo :55 years old, head of the production department of 'The One'. •
Song Yoo-hyun as Oh In-ah :32 years old, head of the design team of 'Lamont', the second brand of 'The One'. Also the team leader of the launching brand 'Claire Mary'. • Kim Bo-jeong as Nam Na-ri :30 years old, manager of the design team of 'The One'. • Moon Joo-yeon as Ahn Seon-joo :29 years old, designer of Ha Yeong-eun's team, honest with her feelings and desires and expresses immediately. •
Ha Young as Jung So-young, 25 years old, youngest member of Sono's design team
People around Ha Yeong-eun • Choi Hong-il as Ha Taek-soo :64 years old, middle school vice principal. He is about to retire in a month. He is Ha Young-eun's father. •
Nam Gi-ae as Kang Jeong-ja :67 years old, mother of Ha Young eun
People around the country •
Cha Hwa-yeon as Min Hye-ok :66 years old. Jaeguk's mother. The youngest daughter of a retail family •
Yoon Jung-hee as Shin Yoo-jeong :40 years old, an influencer with over 600,000 Instagram followers and the managing Director of Department Store 'Hills'.
Others •
Yura as Hye-rin :29 years old, the best celebrity of the era with numerous followers. Her real name is Yang Eun-hee • Ki Eun-se as Seo Min-kyeong :33 years old. Vice President of Vision PR Marketing Team • Kim Do-geon as Jimmy :The One's male casual advertising model •
Shin Dong-wook as Yoon Soo-wan :Yoon Jae Kook's older brother, who died in an accident 10 years ago, and Ha Young Eun's ex-boyfriend. •
Park Bo-kyung as Choi Ji-yeon :Once a colleague of Ha Young-eun at the fashion company 'The One', now the president of an LP bar. Her shop became Ha Young-eun's hideout •
Choi Hyo-eun as Lee Seong-min •
Lee Jung-gil as Yoon Seong-cheol, Jae-gook's father • Kim Young-ah as Choi Hee-ja, A very close and special person who has been working with Ha Young-eun for a long time.
Special appearance •
Lee Do-yeop as Choi Kyung-chan •
Hwang Chan-sung as Kim Soo-min ==Production==