After Crash Landing On You, tvN's Hi Bye, Mama has become the issue of discussion. Especially the role of the protagonist played by Kim Tae Hee's daughter is the talk of the town. The role of the daughter of Kim Tae Hee and Lee Kyu Hyung is played by a boy named Seo Woo Jin. Here is the reason why the production cast a boy for the role of a girl.