OP Eiga

In keeping with his carnival barker roots, Ōkura had moved Shintōhō into exploitation film genres during his time at the studio. Among the genres in which the studio specialized under Ōkura were horror, science-fiction, war, crime and sex films. The same year of Shintōhō's demise, Ōkura founded the Ōkura Eiga studio. Ōkura established his new studio by setting up production in Shintōhō's facilities in Setagaya, Tokyo which he had purchased with his own company. Shintōhō employee Kouichi Gotō bought the studio's Kansai studio as well as the use of the studio name to start up a new enterprise, Shintōhō Eiga. After Ōkura, Shintōhō Eiga is currently the second largest pink film studio.

The early titles produced at Ōkura Eiga indicate that the films from Ōkura's new studio continued the themes pioneered at Shintōhō. Director Satoru Kobayashi's all-color 1963 film, The Mysterious Pearl of the Ama, for example, looks back to Shintōhō's boundary-pushing female pearl-diver films of the mid-1950s, starring Michiko Maeda and Yōko Mihara. Kobayashi also directed ghost stories in the style of the films of Shintōhō's Nobuo Nakagawa, with titles like (1962), (1963), and (1964). Kobayashi continued to occasionally make films in this style for Ōkura as late as 1995 with starring actresses Nao Saejima and Yumi Yoshiyuki, who would become a prominent pink film director herself, releasing mainly through Ōkura.

Kobayashi had worked with Ōkura at Shintōhō since 1954 and came with him to the new studio. Kobayashi's name in the history of cinema was ensured when he directed the first pink film, Flesh Market, in 1962 at Ōkura Eiga. When the police confiscated the film, two days after its release, the studio quickly patched together another version from extra footage, and Flesh Market became a huge success.

The assistant director on Flesh Market, Kin'ya Ogawa who had come from an old Kabuki family, was one of Ōkura's most important directors during the 1960s. One of Ōkura's most experienced and prolific directors, he made his directorial debut in May 1965 with for Kokuei studio. This was the first film in the "Part color" format in which key scenes—usually sex scenes—were shot in color while the rest of the film was in monochrome. Most of Ogawa's output during the 1960s was released through Ōkura. Though Ōkura had established the pink film genre—called "eroductions" until the late 1960s—with the release of Kobayashi's Flesh Market in 1962, Ōkura would not devote its resources entirely to pink until after the failure of Kiyoshi Komori's big-budget war epic, (1962), and the tremendous success of Ogawa's (January 1965).

At Ōkura, Ogawa initiated one of the most popular themes in pink film, the "urban paranoia" story. His trilogy of films beginning with Conception and Venereal Disease (1968) was an example of this genre, in which an innocent country girl is corrupted by life in the big city. Ogawa also directed "pink kaidan" or erotic ghost stories for Ōkura, and it is with these titles for which he is best remembered. Ōkura was involved in the international distribution system involving softcore pornographic films beginning in the mid-1960s. A 1969 report from Kinema Jumpo indicated that some of Ogawa's films for Ōkura, including 1966-06 (June 1966) and (September 1967) had been exported and shown in England. Ogawa claims that his favorite of his films is (November 1968), but most critics name (June 1968) as his best film. Both films were made for Ōkura. Ogawa stayed with Ōkura for six years, joining Million Film in 1970 and later working at Shintōhō Eiga and Nikkatsu.

To help fill the double- or triple-bill programs in his own theatres, Ōkura imported yō-pin or "Western pink" into Japan. These were softcore sexploitation films of the type that were shown in western grindhouses and drive-ins. Ōkura also claims to have produced the first pink film directed by a woman. Kyōko Ōgimachi, an actress in Shintōhō's ama films of the 1950s, directed Yakuza Geisha in 1965. However Jasper Sharp reports that several pink film insiders are skeptical of this claim, as Ōgimachi was Mitsugu Ōkura's mistress, and he was known to treat her with favoritism.

The Weissers write that standard Ōkura Eiga product of the 1960s was a low-budget affair with a forgettable plot which existed only to provide actresses to appear in the nude. One of Ōkura's most popular actresses in their late 1960s output was the shapely Mari Iwai. Iwai was especially known for her roles in coming of age films. Pink film queen Noriko Tatsumi appeared in films for Ōkura, including (December 1967), made between the shooting on Atsushi Yamatoya's cult pink film, Inflatable Sex Doll of the Wastelands. After her career got off to a bad start with cult horror director Kinnosuke Fukada's disastrous foray into pink, Pleasure Trap (Kairaku no Wana, Kokuei, early 1967), actress Keiko Kayama took the unusual step for the time of initiating a publicity campaign. Following this successful move, she became one of the leading sex film actresses of the era, starring in such box-office hits for Ōkura as (April 1967). Ōkura gave future "SM Queen", actress Naomi Tani her first taste of the SM genre in (May 1967), and her first role in a fully SM-themed film with (October, 1967).

Ōkura and OP Eiga in the 1970s and 1980s

By the time the major studio, Nikkatsu took over the sexploitation genre in the early 1970s with its Roman Porno films, a distribution system for independent pink films had been established, with Ōkura and Shintōhō Eiga controlling most of the venues. Ōkura's production arm was eventually named OP Eiga, while the distribution retained the Ōkura name. Typical of the studio's output in the 1980s, director Kazuhisa Ogawa, with regular star Mayumi Sanjo specialized in a series of college girl films. This series had Ogawa seeking revenge for rape, but, unlike typical rape and revenge films, the first offense was not entirely unwelcomed, and the resulting revenge tends to be light-weight acts of humiliation.

(February 1983) and (August 1983) were unusually artistically done, thought-provoking films by regular Ōkura director Dai Iizumi. The Weissers write that Jō Ichimura's 1991 film is a "revolutionary" pink film which has acquired a cult following in the years since its initial release.

Along with the exclusively gay-themed ENK studio, OP Eiga is one of very few studios to regularly produce gay pink film, such as Kuninori Yamazaki's award-winning (October 1993). A former journalist, That's When Things Changed was Yamazaki's directorial debut. Praised by critics for its intellectual themes, it was not as heartily embraced by regular pink film audiences. Openly gay actor-screenwriter Kouichi Imaizumi has become a key figure in the emergence of gay pink film by writing several scripts directed by Yumi Yoshiyuki for OP Eiga which help to bring a more realism to gay-themed pink films.

OP Eiga today