Kamui is a ninja from the Edo period who has decided to leave his clan. After doing so, he is relentlessly pursued by members of his former clan, who consider him a traitor and therefore wish to kill him. Kamui then wanders around Japan to escape them, using his intelligence and great abilities to survive. In the course of the series, Kamui begins to suffer from paranoia because of his status as a persecuted man. He then starts to believe that everybody wishes to murder him and becomes distrustful of everyone he comes across.