Karin doesn't want to be a ninja. Never has and never will. That was until she turned 7 and had to leave her village. Karin doesn't talk about ever having a life before Orochimaru. Nobody's dumb enough to question her, not even Suigetsu.
Karin doesn't mention anything about her lack of a last name. Or about clans. Or about family.
Nobody asks. It might be because they're all in the same boat, or because the last time someone did, they ended up underground in the sewers.
Karin doesn't believe Orochimaru's really gone, and she probably never will. As long as she's only heading in the same direction as Sasuke and them though, it doesn't matter much to her.
Karin doesn't realize the risks their taking just by breathing. Not with Orochimaru, not with Sound, not with Akatsuki and not with Konoha.
She realizes the risks when Juugo and Suigetsu return from scouting the area with cuts and already forming bruises, with ninja hot on their trails.
Karin doesn't care much for teams, or other people. She long ago stopped thinking about others and consumes her thought with her own survival. That was until Konoha came knocking at their door and attacked them. Juugo took a kunai to the arm for her and Suigetsu pulled her out of the way of a powerful ninjutsu.
Now the things Karin doesn't care for are the ones involving herself. As long as they're safe.
Karin doesn't care for Sasuke after a while. It starts when they get ambushed by the Konoha brats and she sees how Sasuke is surprised and pleased with the pink haired girl.
It seals the deal a few weeks later when the pink haired girl lands a good punch on Sasuke sending him into the ground.
Karin doesn't think Sasuke's sane. Not after all the trouble he went through to kill his brother and especially not after betraying Akatsuki for Konoha.
But everyone else rejoices and lets her in on a secret,
It's different for the ones with the will of fire. When she questions them relentlessly for elaboration, all they do is smile and invite her into their ranks.
Karin doesn't really have anywhere to go so she stays with Team Hebi in Konoha.
That's what she tells herself and anyone who bothers to listen.
But she knows the truth; she's become attached to Hebi and the lifestyle of a ninja and if what the blonde jinchuriki promises can actually happen - like everyone in Konoha says - she's ready to take up kunai and shuriken for this pathetic village.
Karin does know that time changes things, and you should never ever expect things to stay the way they are.
Suigetsu mulls that over on his wedding day and wonders if some side effect of Orochimaru's experiments made him crazy enough to marry the stubborn red head.