A Taisho Era Pure Love Revenge Story

Early Taisho period.

Born as the child of a mistress to the prestigious Todou family, Yuu was oppressed and treated like a slave from an early age.
In particular, her older half-sister, Nadeshiko, pretends to be friends with Yuu in front of Shinnosuke, who likes her, but bullies Yuu thoroughly behind her back.
Yuu wishes to be free someday, but cannot do so because she cannot abandon her mother who is imprisoned in a cell.
One day, her mother dies in a fire of unknown cause, and Yuu, who goes to help her, also disappears.

Seven years later, Yuu, who was thought to have disappeared, grew up to be as beautiful as a different person, changed her name to Haruhi, and returned to the Todo family, where she was killed. With her mother's death in her heart, she begins to take revenge.

https://www.cmoa.jp/title/272840/