Sisters in Vengeance

Two babies were swapped at the hospital where they were born. Jiang Yiyi, the Jiang family's own daughter, was raised somewhere else, and Jiang Shuyi grew up in the Jiang house as the heiress. Eighteen years later Jiang Yiyi came back. The household expected a fight over the parents' affection and over the inheritance, with Shuyi as the one who would have to be pushed out. Instead Yiyi attached herself to Shuyi from the day she arrived and stayed there. Shuyi took a while to believe any of it. As the two of them lived alongside each other she came to accept that Yiyi meant it, and they started working together against the people who had been going after them.