Responses
I think they meant more like the word (at least I hope!) Like it was a word that exists on earth but doesn't translate into the new world that they were reincarnated into. I could be wrong though. It didn't really sound like they knew each other from their previous lives, at least to me.
Nah 'Little Sis" is the name of the Otome Game they reincarnated into.
ARE THEY RELATED BACK IN THEIR PREVIOUS LIVES!!!??