《古畑任三郎SP6凶手是大使阁下》这部悬疑片讲述了驻南美某国的日本大使馆发生的一起离奇案件。大使黛竹千代（松本幸四郎饰）以其冷酷无情和奢侈浪费的生活方式引起了当地民众的不满，他利用职务之便大肆敛财。在外务大臣即将访问的重要时刻，参事川北健（及川光博饰）计划召开媒体恳谈会，公布大使的罪行。然而，他却因此引来了杀身之祸。

与此同时，古畑任三郎（田村正和饰）在南美洲度假期间遭遇了麻烦，他的护照被猴子偷走，被迫滞留。幸运的是，他遇到了无处不在的花田（八岛智人饰），找到了临时的住所。不久之后，川北被绑架，并收到了一封勒索信函。然而，这封信件中存在着许多疑点，引起了古畑刑警的怀疑。

古畑任三郎展开了他的侦探工作，揭开了背后的阴谋。他发现大使馆内部隐藏着许多不可告人的秘密和复杂的人际关系。在调查的过程中，他遭遇了危险和阻碍，但他坚持不懈，努力追求真相。

这部电影以悬疑和推理为核心，通过精心构建的剧情和扣人心弦的情节吸引观众。观众将跟随古畑任三郎一起解谜，一步步揭开真相的面纱。同时，电影也探讨了权力腐败和人性的主题，引发观众对社会伦理和正义的思考。

"The Murderer of Ren Saburo Furuhata SP6 is Your Excellency the Ambassador", this suspense film tells the story of what happened in the Japanese embassy in a South American country. A bizarre case. Ambassador Daitake Chiyo (played by Koshiro Matsumoto) caused dissatisfaction among the local people with his ruthless and extravagant lifestyle, and he used his position to amass a lot of money. At an important moment when the Minister of Foreign Affairs is about to visit, Counselor Chuan Beijian (played by Mitsuhiro Kawakawa) plans to hold a media conference to announce the ambassador's crimes. However, he caused a fatal disaster.

At the same time, Ren Saburo Furuhata (played by Masakazu Tamura) was on vacation in South America In trouble, his passport was stolen by monkeys and he was stranded. Fortunately, he met the ubiquitous Hanada (played by Satoshi Yashima) and found a temporary residence. Soon after, Chuanbei was kidnapped and received a blackmail letter. However, there are many suspicious points in this letter, which aroused the suspicion of the Guhata detective.

Furuhata begins his detective work and uncovers the conspiracy behind it. He discovered that there were many unspeakable secrets and complicated interpersonal relationships hidden in the embassy. In the course of the investigation, he encountered dangers and obstacles, but he persevered and worked hard to pursue the truth.

This movie focuses on suspense and reasoning, through carefully constructed plot and The exciting plot attracts the audience. The audience will follow Guhata Ren Saburo to solve the mystery and uncover the truth step by step. At the same time, the film also explores the themes of power corruption and human nature, triggering audiences to think about social ethics and justice.