Too Broken To Be Fixed

Shizuko Nakamura's parents have abandon her in an orphanage, where she stayed for a few months before some nice couple adopted her.
After living with them for ten years they reveal a large secret that they have been keeping ever since they adopted Shizuko. They had a son, Aspen. How they kept the secret? She doesn't know, but she knows he will be her hell.
Shizuko already had bullying problems in school, they are even worse, Aspen does not want a little sister, he thinks girls are stupid and whores. He tries to torment Shizuko as many times as he can.