I Marry the Scumbag Who Killed My Sister and Have Triplets

Her older sister is dead. On a snowy, rainy day, she lies on her back in the snow, heavily pregnant, slowly losing all warmth.

Her parents weep until their voices are hoarse and their eyes are red. She resolves to enter the household as a concubine and avenge her sister.

There are eighteen concubines in the household, and the place is a turbulent mess. She will uncover the culprit who killed her sister, and she won't let a single accomplice get away.