In the near future, science will have figured out how to transfer the spirit of a human being into the body of another. First legalised for therapeutic use, the 'Transfer' has been strictly forbidden since it was discovered that some transferred spirits could become unstable and transform themselves into mass murderers without warning. A police force called 'BATI' was created to stop and quarantine transferred spirits into camps and put an end to the black market of illegal transfers plaguing society.