sworn elder sister; woman one looks up to as an older sister
Refers to a woman who is not a blood relative but is treated like an older sister, often in a close-knit group or mentor-like relationship. The term is honorific and implies respect and affection. Compare with 妹分 (sworn younger sister).
See also: 妹分
She is like an older sister to me and always gives me advice.
In the world of geisha, senior colleagues are sometimes called ane-bun (sworn elder sister).
Compound of 姉 (ane, 'older sister') and 分 (bun, 'part' or 'role'), literally 'older-sister role'. The 分 suffix is used to indicate a social role or status within a group, as in 兄分 (sworn elder brother) or 弟分 (sworn younger brother).