Laotong
Laotong or LaoTong (in English: old sames; written: 老同 in Mandarin) is a type of relationship within Chinese culture, which was practised in Hunan, that bonded two girls together for eternity as kindred sisters.
There were two cultural practises in Hunan in past centuries that acknowledged women's social bonds. One was Laotong, the other was Laotang.