Seo Yoon worked in a long period of time with the singer-actress IU. It started way back to her debut with "Lost Child" in 2008. She has been working with her for many projects like music videos album jacket photos for 'Lost Child,' 'Peach,' 'The Red Shoes,' 'Good Day,' 'Through the Night,' 'Palette,' and 'BBIBBI' as well as her dramas 'You Are the Best,' 'Scarlet Heart: Goryeo,' 'My Ahjussi,' and 'Hotel Del Luna.'

Seo Yoon talked about IU's styling in 'Hotel Del Luna'. She was told that IU's character is a ghost and it is fine if her hair changes as she changes her clothes. She said that they prepared wigs and many ornaments for styling hair. She said that she was able to showcase all her skills in this drama. And she will not regret if her styling job ends right now because she has no more styles left to do.

Seo Yoon styled IU's hair for "Leon" at the "Infinite Challenge" music festival in 2015. She said that IU's bobbed hair was only a wig. They wanted to make IU look like Mathilda from the film 'Léon: The Professional'. However, they could not cut her long hair just because of that. They decided to use a bob wig. Other celebrities noticed that IU had long hair during the rehearsal but had a bobbed hair while filming. They asked her if she quickly cut her hair in the waiting room. This became a hot topic.

Seo Yoon recalled spending a long time working with IU. She considers IU as her muse. She described IU as someone who has a very small frame but has a high caliber. Whenever she does drama or her album, she always checks everything is going well. She even checks the staff if they have eaten.

Seo Yoon recently worked with for Sulli's solo track "Goblin." She described Sulli as a girl with pale skin and dark hair. She thought it is best to make Sulli look different than her normal look since it was her first album. She said that there were no problems and they dyed her pink just to match the dreamy nature of the song. She also worked on making Sulli's hairline thick to make her face look small and defined.

Seo Yoon also shared her experience of styling the hair of male idols. She worked with B1A4 on their styling for "Sweet Girl". She said that it was hard to make short hair look different.

She also mentioned working with many girl groups including 2NE1 and PRISTIN. She is now working with Oh My Girl more. She said they looked even prettier in real life than on screen.

Seo Yoon revealed that her styling was inspired by Girls' Generation's Taeyeon and BLACKPINK's Jennie. She is hoping that she can work with BLACKPINK someday.