moved in with Inoue. He also wrote rough drafts for a number of Inuoe's scripts. Nikkatsu The Nikkatsu Company, having ceased film production during World War II, restarted in 1954 and lured assistant directors from other companies. Masuda joined the studio as an assistant director and writer. He continued to write scripts for and with his mentor Inoue, who had also made the switch. He served as 1st AD to Kon Ichikawa on the sets of The Heart (1955) and The Burmese Harp (1956). Masuda was promoted to director in 1957 and debuted with A Journey of Body and Soul the following year. It was a B movie, a low-budget film meant to fill out a double feature, but he quickly ascended to the A list that same year. Rusty Knife (1958) marked Masuda's third film and first major hit. It starred Nikkatsu's top Diamond Line stars Yujiro Ishihara and Akira Kobayashi. They play two hoodlum brothers who attempt to go straight but witness a murder and find themselves pursued by the killers. The script was written by Ishihara's older brother, and future governor of Tokyo, Shintarō Ishihara. Yujiro Ishihara was by far the studio's biggest star and Nikkatsu frequently paired their young stars with young directors in order to make "new types of films". Masuda, who turned 30 during the production, made a total of 25 films with Ishihara, more than any other director at the studio. Rusty Knife also marked the first in a succession of hits for Masuda which would serve to keep him in the action genre throughout the next decade. Masuda and Ishihara's follow-up, Red Quay (1958), was based on the 1937 French film Pépé le Moko. In 1962, the duo's Hana and Ryu was the studio's number one hit. It was also Masuda's first jidaigeki (period drama) and predated the popularity of the ninkyo (honour versus duty) subgenre which began in 1963 and continued late into the decade. However, Masuda's biggest hit was Red Handkerchief in which Ishihara stars as a disgraced police detective–cum–construction worker who shoots and kills his girlfriend's father. It was the third-highest grossing domestic film of 1964 and a blueprint to the mood action subgenre, action–romantic drama hybrids in a film noir–like setting which were popular in the mid-1960s. He also worked frequently with Kobayashi and Rusty Knife was credited with making the actor a star. By the late 1960s,