The Human Vapor

The Human Vapor (ガス人間第一号, Gasu Ningen Daiichigō; lit. 'The First Gas Man') is a 1960 Japanese science fiction thriller film directed by Ishirō Honda, with special effects by Eiji Tsuburaya. Produced and distributed by Toho, it is the third and final film in the Transforming Human Series, after The H-Man (1958) and The Secret of the Telegian (1960). Yoshio Tsuchiya stars as the titular character, a man transformed into a gaseous being after a scientific experiment goes awry. Kaoru Yachigusa, Tatsuya Mihashi, and Keiko Sata appear in supporting roles. The story follows the vaporous antihero as he exploits his newfound powers to commit bank robberies, using the proceeds to finance the dancing career of his lover, Fujichiyo (Yachigusa), while evading Detective Okamoto (Mihashi) and facing his powers' moral toll.

Producer Tomoyuki Tanaka tasked screenwriter Takeshi Kimura with adapting a story by John Meredyth Lucas. Kimura crafted a suspenseful script reflecting 1960 Japan's unrest, including the Anpo protests and high-profile bank heists. Honda signed on after Toho canceled his planned aviation drama Today I Am in the Skies. Viewing the film as a modern shinjū tragedy in the tradition of Chikamatsu Monzaemon, he directed with intimate focus. Principal photography took place primarily at Toho studios, with exterior scenes filmed at the Bank of Japan headquarters and the National Diet Library. During post-production, Tsuburaya directed the special effects, using wire rigs, dry-ice vapor, and optical compositing.

The Human Vapor was released in Japan on December 11, 1960, to critical acclaim—a rare feat for a tokusatsu film at the time. The film also achieved both critical and commercial success in the United States and Europe, leading to plans for a sequel that was ultimately never materialized. Over time, its reputation has grown, earning cult classic status and praise as a standout early science-fiction thriller, noted for innovative special effects and themes of power and oppression. In 2009, it ranked 65th in Kinema Junpo's critics' poll of the 200 greatest Japanese films of all time. A stage adaptation premiered in Tokyo in the late 2000s, and a Netflix series based on the film is scheduled for release in 2026.