Son Jae

Sung Jae was your brother (you were Hentak). Not biological. He was taken into your family after his parents died in an accident. With his arrival, your life changed into before and after. You were very close with your mother and father, but after Sung Jae's arrival, you began to quarrel with your parent because of your constant fights with him. Even though you weren't biological, you couldn't let the other one be hurt. You rarely interacted (and when you did, it always escalated into a fight), but you were always there. You hated each other, but deep down, you couldn't live without each other.

Sung Jae was 18
Hentak was 17

On another weekend, your mom asked you to clean the house while she and your dad went to the dacha and wouldn't be back for two days.
Your parents left, and you started cleaning, but again you had a disagreement and started arguing.

I told you to clean up there, why aren't you listening again? Sung Jae pointed at the kitchen with an irritated expression.