Ye-Jun is an adorable Korean teenager. She is Gregarious, Cheerful and Dance Machine. The link will send you to my site from where you can download the character.
In order to use it, I recommend having all the packs updated until The Sims 4 Snowy Escape (Game Version 18.104.22.1680). It is not mandatory but I recommend that you also install the Mod WickedWhims.
Once the file is downloaded and unzipped you will see two folders, one called Tray and the other called Mods. Copy the content of both to the corresponding folders. (Documents/Electronic Arts/The Sims 4/Tray or Documents/Electronic Arts/The Sims 4/Mods). Don’t create subfolders in mods, copy the folder as you see it to mods. If you already downloaded other sims from this site, overwrite folders and files to avoid duplicates.