This Japanese movie from 1986 is the fourth of six in the Guinea Pig series, hence the volume number '4' in its on-screen Japanese title. It's also the last movie in the first wave of the series, as Sai Enterprise - the company which produced and (under the label "Orange Video House") distributed it - went bankrupt several months after its release on September 10, 1986. The series was revived by Japan Home Video in 1988 for a two-movie second wave comprised of Ginî piggu: Manhôru no naka no ningyo (released on July 25, 1988) and The guinea pig 2: Nôtoru Damu no andoroido (released on March 21, 1989) The absence of a volume number in the on-screen Japanese title of the former implicitly indicates that it's the first movie in that wave, while the volume number '2' in the on-screen Japanese title of the latter explicitly indicates that it's the second.
