The White Tiger Clan's Baby Cotton Ball

Soya was the beloved youngest daughter of the Vermilion Bird family—at least, until her first transformation.
Instead of the red feathers that all true descendants possess, she sprouted snow-white fluff.
"Extract her spirit core and lock her in the cold palace."
After that day, Soya became the family's disgrace, facing neglect and abuse. When the real daughter, Liri, finally returned, Soya was thrown away.
Right at the brink of death—
"What is this fluff?"
She was rescued by the head of the White Tiger family.
"I think I'll steal you, you little fluff."
Soya accepts his suspicious offer and moves to the land of the White Tigers. She just wants to live quietly without drawing attention to herself, but the people of the White Tiger family are being way too nice to her!