younger sibling (polite)
동생분은 어떠세요?
How is your younger sibling?
— TAR 타르 (2022)
동생분 한테 안부 전해줘요
Please give my regards to your younger sibling.
— Kill Boksoon (2023)
그 동생분은 쌍둥이 였던 것 같군요
So it seems your younger sibling was a twin.
— 안드레이 루블료프 (1966)
동생분 있잖아요 같이 이사 안 가고 혼자 여기 그냥 있는 거 예요?
Your younger sibling isn’t moving with you, right? They’re just staying here alone?
— Oasis (2002)