Moviegoers in Japan are generally expected to take a vow of silence at the cinema — unless the film happens to be "The Rocky Horror Picture Show."

The musical comedy about white-bread newlyweds who stumble upon a creepy castle full of kinky humanoid aliens from the planet Transsexual was a flop upon its initial 1975 release, but then a New York art house revived it as a midnight movie the following year. The audience began to ad-lib bawdy call-and-response banter with the actors while others stood in front of the screen dressed (or undressed) in character to pantomime the dance sequences. Props such as toilet paper, playing cards and hotdogs flew through the air on cue. The cult of Rocky Horror was born.

These so-called shadowcasts arrived in Japan in 1988 when the film's distributors brought over "Rocky Horror" fan club president Sal Piro to teach an innocent public the ins and outs of audience participation. Now Lip's, Japan's oldest shadowcasting group, carries on the tradition with sporadic performances, the largest of which is held at the end of October in conjunction with the Kawasaki Halloween parade. Lip's president, who goes by the pseudonym Betty Boing, recalls the difficulty of getting early audiences on board.