Untrusted

A girl named Lia—now going by Zero—killed her parents and lost her brother in an accident, leaving her with no friends for years. Being lonely and depressed for some time, she later finds out her brother was killed not by accident, but on purpose. Even more sorrowful, she strives to kill the person who murdered her brother. When she enrolls in a new school, though, she meets a few people who have a huge impact on her life.