Kurumi: The Spirit Assassin

Discover the story, a spirit, who has a job to kill people to get her life in order. But, one day, she gets a job to assassin a family, a very popular one, and she'll get full of riches in return. On her journey to find and kill the family, she meets a lot of people who want to join her, and some, that want to kill her.
And, this spirit never gives up and cares about no one, because, she is Kurumi Tokisaki