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.

“People weren’t used to the idea of going crazy at the movies,” she says. “Fan club members got yelled at, or even punched for being loud. They did all they could to make the theater staff and audience understand that it was more than an excuse to act rowdy.”

In a pre-Internet age, the rules of audience participation were a sort of secret handshake only knowable through subculture magazines, word-of-mouth or pre-screening lectures. For some, like Boing, dedication to the film follows you home from the theater. She wears her hair in a short black perm to match the character she shadows, Dr. Frank-N-Furter, the mad scientist-cum-sweet transvestite from Transsexual, Transylvania.

She and fellow Lip’s members travel abroad to conventions to meet other fans, invite performers back to Japan and, of course, pick up new gags. Boing explains that showings in Japan are similar to those in other countries, except Japan emphasizes audience participation by riffing on the Japanese subtitles or intentionally misheard dialogue.

” ‘I see’ sounds like ‘ashi,’ the Japanese word for ‘foot.’ So before an actor says ‘I see’, the crowd yells, ‘Where are my shoes?’ and it sounds like the actor responds with, ‘On your feet.’ ” Silly to be sure, though it follows the same logic as throwing rolls of toilet paper when a character blurts out, “Great Scott!”

Lip’s have been performing shadowcasts at the Kawasaki event since it began in 1997. Members of the group were pioneers at a time when the public didn’t care much about Halloween, much less how to dance the “Time Warp.” According to Boing, the organizers consider Lip’s an essential part of the event, a fair assessment given that its performance draws a theater crowd of more than 500.

The Oct. 25 screening will feature costume and lip-synch contests in addition to a special surprise to celebrate the film’s 40th anniversary. Bring rubber gloves, newspapers and any unsuspecting virgins you may have lying around. But don’t be late. The Master doesn’t like to be kept waiting, and tickets are only available on the day.

“The Rocky Horror Picture Show” takes place at Cine Citta’ in Kawasaki-ku, Kawasaki, on Oct. 25 (6:30 p.m. start; ¥1,000 or ¥500 in costume). For details, visit www.lacittadella.co.jp/halloween/.