Drive Away the Green Tea Sister

When I was ten years old, my parents were afraid that I would be lonely, so they adopted a girl about my age from an orphanage. She is a good girl in front of her parents, but very arrogant in front of me. Later, she and I were admitted to the same university, and I always regarded her as a sister. It wasn't until one day that he teamed up with my boyfriend to kill me... That I knew their true identities.