In the most recent episode of “True Beauty,” Lim Jugyeong (portrayed by Moon Ga Young) wore this coat when she went camping with her classmates. This was also same outfit she had when Han Seojun (portrayed by Hwang In Yeop) comforted her while she was crying, and during her *spoiler warning* kiss scene with Lee Suho (portrayed by Cha Eun Woo).
This coat is actually called a jumper from the Korean brand ON&ON, and is priced at 359,000 won (or around 15,736.94 PHP).
You can buy the coat here, they’re also selling the coat at a discounted price!