The films of Akira Kurosawa used to be the gateway into Japanese cinema for many non-Japanese. (That role has since been assumed by the films of Hayao Miyazaki and other animators.)

Kurosawa’s classics of the 1950s, such as “Rashomon,” “Ikiru,” “Shichinin no Samurai” (“Seven Samurai”) and “Kakushi-toride no San-akunin” (“The Hidden Fortress”), not only crossed borders with their universal themes, vivid characters and compelling stories but had an outsized influence on foreign filmmakers. One was George Lucas, who famously drew from “The Hidden Fortress” to create “Star Wars.”

A key scriptwriter on these and other Kurosawa classics was Shinobu Hashimoto, whose career spanned six decades — and he is still with us today at age 97. A 2006 memoir, “Fukugan No Eizo: Watashi to Kurosawa Akira,” of Hashimoto’s years with Kurosawa has now been translated into English as “Compound Cinematics: Akira Kurosawa and I” by Lori Hitchcock Morimoto.

The book also details Hashimoto’s professional life before and after Kurosawa. After apprenticing with Mansaku Itami (1900-46) — a highly respected prewar director and scriptwriter (and father of director Juzo Itami) — Hashimoto scripted some of Japan’s most critically acclaimed and commercially successful postwar films. These include “Watashi wa Kai ni Naritai” (“I Want to Be a Shellfish”), a hit 1959 drama about an innocent man sentenced to death for war crimes that Hashimoto also directed, and “Seppuku” (“Harakiri”), Masaki Kobayashi’s bitingly critical 1962 examination of the samurai ethos, later remade by Takashi Miike.

Hashimoto became not only a member of what he calls “Team Kurosawa,” but a top-flight scriptwriter in his own right with strong views on his craft, especially in connection with Kurosawa.

By when he first joined that team, for the film that became “Rashomon,” Kurosawa was an established director and Hashimoto, eight years younger, was still a beginner. Instead of trying to overawe his young collaborator, however, Kurosawa promptly accepted Hashimoto’s suggestion to combine two of Ryunosuke Akutagawa’s short stories (“Rashomon” and “In a Grove”) into one script.

Also, when Hashimoto realized he had no idea how to do this, Kurosawa rescued him — and the film — with the simple-but-brilliant reframing, by starting the story at Kyoto’s Rashomon Gate, with characters taking shelter from the rain talking about the events of “In the Grove.”

“Good intro, flawless story progression, everything proceeding apace,” Hashimoto writes admiringly of Kurosawa’s rewrite.

But their collaboration didn’t always go swimmingly. When Team Kurosawa reached a similar impasse with the script for “Ikiru” — co-scriptwriter Hideo Oguni noted that the bureaucrat hero was destined to die off too soon in the story — the director angrily shredded the pages over which they had so painstakingly labored. Kurosawa’s face, Hashimoto writes, was that of a “richly painted red demon.”

The collaborators finessed this problem by having the mourners at the hero’s funeral relate his transformation from time-serving drudge to courageous campaigner for a children’s park, rather than relate his entire story chronologically, which Kurosawa and Hashimoto thought would be obvious and boring.

After this one flare up, Hashimoto notes, “nothing happened, the going was smooth,” and the film was proclaimed a masterpiece.

In addition to his quick temper, Kurosawa was a demanding perfectionist and a relentless worker.

“According to him, the work of writing a script was like running a full marathon,” Hashimoto recalls. This combination made the task of scripting the 504 pages of “Seven Samurai” a lengthy ordeal. Hashimoto writes that the three scriptwriters were, “tottering on in total exhaustion like somnambulists.” When they finally finished, Hashimoto felt proud of what they had accomplished, as well as “liberated from Team Kurosawa — and Akira Kurosawa.”

He soon broke his vow to never work with the director again, however, teaming up with him for “Ikimono no Kiroku” (“I Live in Fear”), a 1955 drama about an elderly businessman (Toshiro Mifune) whose terror of nuclear war threatens to tear apart his family and destroy his life.

Rather than using the method of his previous collaborations for this film — where one scriptwriter (Hashimoto) composes a draft and another (Oguni) monitors and critiques the subsequent revisions — Kurosawa decided that he and his team would write the final version together from start to finish. This change saved time, but “I Live in Fear” was a critical and commercial failure.

Nonetheless Kurosawa refused to abandon this “straight to the final draft” system — and Hashimoto dates his decline as a filmmaker from this time on.

“Things took a turn for the worse and slipped into the shadows,” he writes.

But Hashimoto applauded “Yojimbo” (1961), a Western-style film about a masterless samurai, which was scripted with this system and became Kurosawa’s biggest hit in years. And he worked with Kurosawa on the in-the-slums drama “Dodes’ka-den” (1970), which got a chilly reception from audiences and critics.

After that, Hashimoto viewed the director’s struggles from afar.

The period epics “Kagemusha” (1980) and “Ran” (1985) bored him while the intimately personal omnibus “Dreams” (1990) delighted him. But for Hashimoto there was to never be another “Seven Samurai.”

For any fan of Kurosawa or student of scriptwriting, this is a fascinating and enlightening must-read; though, as scriptwriters will, Hashimoto inflates his role in Kurosawa’s oeuvre. And he has little to say about the director’s efforts on the set or in the editing room.

Also, for all the verve of its anecdotes and the insights of its analysis, the book suffers from Morimoto’s clunky, tone-deaf, overly literal translation. One example among multitudes: “We had to be kidding, a scenario close to 500 pages was, boy, no, what on earth was it turning into?” What on earth was the editor thinking?

That said. Hashimoto is a major figure of Japanese cinema’s Golden Age, as well as one of its last survivors. He is also an informed and opinionated source on Kurosawa, the director of that era best known to the outside world.

Hashimoto’s voice — however garbled, through no fault of his own — deserves to be heard.