The H-Man rates as one of the most genuinely frightening Japanese horror films of the 1950s. When a minor-league drug runner completely vanishes, leaving only his clothes behind, detective Tominaga (Akihiko Hirata) investigates. Along the way, Tominaga makes the acquaintance of scientist Masada (Kenji Sahara), who theorizes that the missing doper was melted into a liquid "H-Man" as a result of being exposed to nuclear radiation. Sure enough, the H-Man soon resurfaces, seeking out victims to "dissolve" so that he can continue to survive. Director Inoshiro Honda's matter-of-fact approach to the material is far scarier than any of Honda's scream-and-shout "giant monster" pictures from the same era.
by Hal Erickson synopsis