Three musicians get lost on the way to visit a friend's grave. They become irritated and start to quarrel.

Due to the development of self-driving AI, traffic accidents are drastically decreased in 2027. Amane Yonago, a new Prosecutor, is assigned to the Transportation Division. Unhappy with her new job, she decides to indict the self-driving car’s AI which crossed the center line in error and caused an accident. The instant the trial begins, the AI admits that they killed the victim on purpose. Because of this allegation, Amane Yonago must find a way to prove the AI has feelings.