>>3684954I don't think they are related, because Kale calls her "Ane-san" and not "ane" or "aneue.
"Ane-san", when used by Japanese yakuza or gangs, means madam, or a lady who is their senior.
"Ane" or (rarely) "aneue" is a common way of saying "big sister" in rather formal situations.
So,Caulifla is only called that, because they're in a gang and she's the leader (the manga expands on this more than the anime btw).
There's also "Onee-sama", but that has three main uses in modern times:
1. An idol-follower relationship between young women, usually signifying extreme adoration on the part of the follower.
2. A subset of the first type of relationship, signalling a lesbian relationship with the uke referring to the seme as "Onee-sama", i.e. the Onee-Seme.
3. Identification of a very formal and traditional relationship between sisters. Most likely to be used by very traditional families (miko, samurai, Yamato Nadeshiko, etc.). Tends to be a sign of awe rather than affection. (Awe can mean either adoration, or a type of fear.)
Number 2. is obviously my favorite, especially in the context of Kale and Caulifla, but the anime hints to a combination of 1 and 2..
