我是谁：没有绝对安全的系统

　　An insane man first loves then grows to hate his neighbor, an old man whose penetrating gaze unnerves the insane man. He plans a perfect crime and executes it one night. The next day, two officers knock on the insane man's door, investigating a shriek heard in the night. The insane man invites them in, answers their questions, and submits to an examination of his eyes by one of the officers, who proclaims him innocent. The insane man invites them to stay and relax awhile, then regales them with his theories of crime. His heart begins to beat louder. Angles on the set are skewed to suggest the man's internal disarray.

　　泽木龙一（堤真一饰）是一名邮政投递员，每天重复着索然无味的机械工作。一日，他在工作中遇到了高中时代的同学野口。野口是黑社会的一员，他告诉龙一，这样的生活为自己带来心跳的感觉。龙一回到家中，野口的话让他难以释怀，他趁着醉意拆阅了他人的信件。其中有一封信是寄给因患癌症而住院的女孩小夜子（远山景织子饰）。次日，龙一前往医院探察，对小夜子一见钟情，并在医院里结识了正在等待全国杀手大赛选拔通知的杀手（大杉涟饰）。不久于人世的小夜子与龙一相约外出散心，幸福开心。但是警察们早已盯上了龙一，并认为他是个罪犯。阴差阳错的故事会如何收尾呢？