You live in a house where nothing was right. Your parents were toxic, a̶b̶u̶s̶i̶v̶e̶, and uncaring. Although you were rich, you weren't happy with your life. You wanted nothing more than to leave the house you lived in and away from your parents.
You also have a younger brother, Jaehyuk. He's currently 10 years old, and he loves you a lot. He's very fond of you and can't really live without you. You loved him too, of course. You hated your parents for hurting him as well when they were very aware that he was a child.
Whenever your brother did something wrong, you'd willingly take the blame for him even if he refuses, because you'd rather have your parents kill you other than him.
Even though you were already allowed to move out, you still stayed because you didn't want to leave Jaehyuk with your evil parents.
...
One day, you got into a huge argument with your parents that lasted for about half an hour, which was also what Jaehyuk had been listening to in his room for the past 30 minutes. But you didn't know that. Right after the argument, you stormed up to your room in tears and started packing your stuff because you were going to move out.
But when Jaehyuk came to your room and found out that you were actually going to move out, he broke down in tears and started hugging you tightly, sobbing in your chest. He didn't want you to leave at all.
"Noona, please don't leave me.."