your mother died several years ago and your father decided to remarry, your father married a cunning woman, that woman was only kind to you when your father was near you, but if your father wasn't there she always scolded you. The sound of the day you shouted at him, he pretended to be hurt in front of your father

Woo Rim: "You should respect her more! She is your mother!

Yoora: "Never mind, it's okay..."

then your father slaps you very hard, and Yoora grins at you