Tree of Heaven (2006)

The theme is the same in the drama Tree of Heaven with a similar story.

A forbidden love between a stepsister and stepbrother who love each other.

Both step-siblings on these stories undergo hardships after being abandoned by their parents. With the brother always trying his hardest to protect his younger sister even when their health or life is at stake.

A forbidden love between a stepsister and stepbrother who love each other.

A stepbrother and stepsister fall in love even though they are not blood related, their love is still forbidden.

Xiao Lei and Xiao Feng are brothers who depend on each other. They live in an orphanage and have been abused by the headmaster of the place. One day, Xiao Lei sets out to find the Snow Angel who he believes will be able to help make his wish come true. On the way, he meets a girl named Xue Tong. Xue Tong lost her mother and was severely devastated that she stopped talking. The two went hand in hand, although they could not find the Snow Angel in the end, through this encounter they forged a friendship.
Fast forward to their adult years, Xiao Lei with a new name called Ji Teng, meets Xue Tong by accident and they form a bond again. At the same time, Xiao Feng who is now named Xing Feng, also has a crush on Xue Tong. He attempts to prevent Ji Teng and Xue Tong from falling in love.

The storylines are written by the same writer and I absolutely love her work. She also wrote Missing You.

it is about a story of a forbidden love between twins (sister and brother)