I'm rewatching the whole SAO series and I go to the manga whenever I want to clear things up for the show but I thought about something.
In the Aincrad novels, there are specific chronological Arcs for:
Silica, Lizbeth, Yui, Sachi
But in the second season, we see Sinon, a "main?" character. But isn't there a specific Arc for her? or some more backstory than what we see in the Anime?
The fact that she gets scared of guns but in-game she isn't, and her past at the bank.
I couldn't find any Arcs for the characters of the second season so if there are where can I find them or what are they called?