Duty
Sango has never failed to do her duty.
Not as a daughter.
She was a good daughter, you know. Always managing to do chores, to smile and obey and to learn to sew and feed the chickens on time and getting up… and everything.
She learned to make her father stand tall, his chest swelling with pride as her small (they were so babyish) hands wielded metal, bone and all manner of weapons.
She didn't fail to make her father proud- she was a good daughter.
Sango didn't falter in her duty as a sister either.
Every single scar, every single heartache, every single heartbeat… she never hated her brother. Kohaku… he was made from her and she was made from him—they were the same.
We're just two bodies of one soul… Kohaku and me.
She lived and died for her brother- and died again and again for him. Because it wasn't fair that her little brother, with those tiny shoulders, should bear that horrible, heavy burden by himself. She was a good sister.
She didn't fail her duty to Kohaku- because not once did she glance at him with hate, even if he stabbed her with that chained scythe.
It's nothing compared to what he's going through. She would say with a sad, small voice.
Her duty as the demon slayer?
Sango has never failed a single mission, not the professional ones. After all, you couldn't fail your duty when people's lives are on the line. She wasn't a daughter, sister or even a woman when she became Taijiya. Her humanity was still there—but perhaps it was merged with her boomerang of a weapon. Hiraikotsu. She became like her weapon.
When you realised what Sango was, what her duty was… it was like the thunderbolt strike of her Hiraikotsu.
But perhaps… Sango shouldn't really have had such a perfect record…
Because failure festers inside of her like some disease, spreading from cell to cell until Sango doesn't know what it is like to win.
What it is like to be a daughter. A sister. A woman. A taijiya.
What is it like Kagome-Chan… to have your brother call you by your name?
What is it like Inuyasha… to be that strong?
What is it like Houshi-Sama, to still think about a future and a life?
What is it like Shippo, to have clean hands and innocent dreams?
What is it like Sesshoumaru, to stand that tall?
Is she being a bad human by being a good sister when she wants Kohaku to live? That sacrilegious thought, the ungodly wish that maybe her brother, who shouldn't have died, should live?
Sango may have been good at everything else before…
But right now…
She was failing as a human being…
And she knew that Naraku knew that she knew it too.