My Sister's Affair (GL)

Isabella Ruby Miller had only one aim when she started high school and was transferred to Justice High: she wanted to be popular and shine out academically and in extracurricular activities. She desired to be a member of the popular group in order to avoid repeating her unpleasant experiences from elementary and middle school.
Isabella found out that her beloved stepsister, Gianna Luna Davis, is the bullies' preferred prey. Isabella pretended to dislike Gianna at school and kept the truth about her actual feelings for her until she could. Worse, Isabella became a bully for Gianna.
How far will Isabella go to keep the truth about her and Gianna from the other students at school? To what extent can Isabella conceal her actual self and disregard her increasing romantic feelings for her stepsister?