転生したら剣でした (Series) favorite_border

Volume 1 synopsis: A nameless slave — a girl of the black cat clan. Bound by the coercive power of a cursed collar, she cannot escape, and spends her days enduring abuse as she waits to be sold off… Then one day, the girl witnesses something that changes everything…!? The massively popular novel that won the 4th Net Novel Grand Prize, now magnificently adapted into manga!