1.
older sister (my older sister)
Humble term used when referring to one's own older sister when speaking to others outside the family.
姉 is the humble term for one's own older sister, used when speaking to people outside the family.
FAMILY TERM SYSTEM:
- 姉: my older sister (humble, to outsiders)
- お姉さん: older sister (polite, someone else's or direct address)
- お姉ちゃん: big sis (casual, direct address within family)
USAGE NOTES:
Within the family, children often call their older sister お姉ちゃん or by name. 姉 is specifically for describing your sister to others.
RELATED FAMILY TERMS:
- 兄: my older brother (humble)
- 弟: my younger brother (humble)
- 妹: my younger sister (humble)
The pattern is consistent: plain forms for your own family members, お〜さん forms for others' family members or polite address.