During Kurosawa's most productive period, the late Forties through the early Sixties, he worked with many of the same cast and crew on many films. The familiar team, that worked well together, contributed to the successful production of these movies. Here's a brief list of some of the frequent and notable actors in Kurosawa's "stable.
First, there is Toshiro Mifune; he stands alone, by far the best-known to Western audiences. Then, two others, Takashi Shimura and Minoru Chiaki, played many large roles in Kurosawa's films of the era. All three actors appeared in many of them. Then, there are several other actors, some of whom had big roles in one or two movies, some of whom had small roles in many films. This is not an exhaustive filmography, for particular actor or movie, you can check IMDB.
He and Kurosawa formed the greatest actor-director team in cinematic history. They both seemed to bring out the best in each other. Their first film together was Drunken Angel in 1948, their last Red Beard in 1965. Altogether, they collaborated in 16 films, including almost all of Kurosawa's greatest from that period: Rashomon, Seven Samurai, Throne of Blood, The Lower Depths, Yojimbo, Sanjuro, etc.
Sadly, the two men had a falling out after Red Beard and never worked together again. During the protracted filming of Red Beard, Mifune had to wear a beard for the part, and could not get other work, as he always had while making previous movies. With his high life-style, it was a real financial strain for him. Mifune famously said, "I am proud of nothing I have done other than with him." Quite a statement, considering that, out of Mifune's 180+ films, he worked with Kurosawa on 16.
Mifune had an explosive, dynamic quality as an actor, capable of rapid changes of emotion. He was very hard-working, always early on the set, and (as his son related in a posthumous interview) a very orderly person, the type who arranged his cigarette butts in rows in an ashtray.
Top photo: Mifune as Sanjuro in Yojimbo
Frequently paired with Mifune, as a father figure: police detectives in Stray Dogs, doctor and patient in Drunkel Angel, leader and misfit in Seven Samurai. In Kurosawa's early films, Shimura frequently was the star or co-star; his leading role in Ikiru, as Watanabe, the thirty-year civil servant dying of stomach cancer is priceless. The top pictures is from Ikiru, wearing his symbolic new hat as he tearfully sings "Life is Brief." As time went on, Mifune moved to center stage, and in later films, notably Throne of Blood and Yojimbo, Shimura plays quite secondary parts.
Shimura appeared in 20 Kurosawa movies. Other notable roles included Kambei, the leader in The Seven Samurai, the Woodcutter in Rashomon, and lawyer Hiruta in Scandal (not a great film, but in the role of Hiruta, we see a foreshadowing of Watanabe in Ikiru). His style was more solid and avuncular than Mifune's, with possibilities of sadness.
He also starred in the 1954 monster movie, Gojira (Godzilla), which was really an anti-nuclear movie.
Top photo: Shimura as Watanabe in Ikiru
The third of Kurosawa's leading actors, he usually played somewhat lighter, more humorous characters, such as the good-natured Heihachi in The Seven Samurai. He appeared in nine Kurosawa movies. His role as the questioning, philosophical priest in Rashomon, was, for him, a little out of character. I got a kick out of his Noguchi, one of the low-level bureaucrats in Ikiru. Probably his most acclaimed role is the quarrelsome peasant Tahei in The Hidden Fortress.
Top photo: the priest in Rashomon
His firm, square-jawed appearance reminds me a little bit of the American actor Glenn Ford. He was Kurosawa's first leading man, with top roles in the early films: Sanshiro Sugata (top photo), No Regrets for Our Youth, and The Men Who Tread on the Tiger's Tail. Mifune's star eclipsed his in the early Fifties, and his later Kurosawa roles were secondary: as Master Homma in Yojimbo, a detective in both The Bad Sleep Well and High and Low, and General Hyoe Tado in The Hidden Fortress.
He never rivalled Mifune, but after playing some co-starring roles in the early Sixties, in Yojimbo, Sanjuro, and High and Low, he took the leading parts in Kagemusha and Ran. His role as a "non-villain," a likeable intelligent detective in High and Low (top picture) was a welcome change of pace; he played that very well.
One of the leading Japanese stage and film actresses of the era, she only played in three Kurosawa films. Her biggest role was Lady Asaji (the Lady Macbeth figure) in Throne of Blood. But, perhaps it's my Western tastes, but I enjoyed her as the evil, scheming, landlady Osugi in The Lower Depths even more. (top photo)
The second image, heavily made-up in Kabuki style from Throne of Blood, is not the greatest. I prefer the first one from The Lower Depths. Neither capture her appeal; in her own villainous way, she's quite something.
A regular, he appeared in all but two of Kurosawa's films, usually in bit parts. His most memorable role, that of the drunken actor in The Lower Depths (top picture), is marvelous: "Alcohol has poisoned my bitol organs." But in another substantial part, that of Sub-section chief Ohno, in Ikiru (2nd), I can hardly recognize him as the same actor. He also played the father and farmer, Manzo, in The Seven Samurai (4th); the deranged merchant, Tazaemon, in Yojimbo, and the peasant Matakishi in The Hidden Fortress, the victimized mid-level executive Wada in The Bad Sleep Well (3rd), and the dying wordless Rokusuke in Red Beard.
With his hangdog, tragi-comic, Emmett Kelly face, Hidari is one of the most recognizable of the Kurosawa supporting players. His largest role was that of the thoughtful, kindly priest Kahei, in The Lower Depths (top picture). But perhaps, a more typical role for him was the peasant Yohei in The Seven Samurai. (3rd). The second picture shows him as a low-level civil servant in Ikiru. He has a few words as a patient in Red Beard.
She usually played a motherly or grandmotherly type. Usually in secondary roles, her largest part probably was as the wife of the lead character in I Live in Fear. While she's on-screen a lot, and her character is important, most of her presence (as the dying tinker's wife) in The Lower Depths is unseen, just her coughing and moaning is heard.
His rounded, somewhat porcine features, are also fairly recognizable. His best role was as the aptly-named Inokichi ("Boar") in Yojimbo, a dimmed-witted but murderous brother. He also showed up as an absurdly threatening yakuza in Ikiru.
Top photo: the policeman in Rashomon (a small role)
Mori was an established Japanese actor, who was quite famous indepently of Kurosawa. His best-known role as the samurai-husband in Rashomon (top photo). He also had large roles in The Bad Sleep Well and The Idiot.
Most well-known as the young samurai, Katsushiro, in The Seven Samurai.
Top photo: a young intern in Ikiru .
She played several major female roles from the mid-Fifties through the mid-Sixties, notably Okayo in The Lower Depths (top photo).
Typically cast as an unctuous bureaucrat, his role as the Deputy Mayor in Ikiru is very well done (top photo).
He also appeared as The Commoner in Rashomon.
Playing older roles, his most memorable was the alienated, furiously pot-scraping tinker, Tomekichi, in The Lower Depths. (top photo) Another big part for him was Gonji, the innkeeper in Yojimbo.
He appeared as the landlord Goheiji in Red Beard, uncharacteristically clean and presentable, out of his usual scruffy character.
I tend to confuse him with Eijiro Tono, both men playing older types. Indeed they were paired up in Yojimbo, with Watanabe as the coffin-maker. He also appeared, in a similarly-appearing part as Kuna, in The Lower Depths (top picture). In Ikiru, he has a small role as a patient describing the symptoms of stomach cancer at length, which is not to be missed. In this role (see second picture), he looks much younger than in his other parts. Like other bit players, he appeared in Red Beard.
A beautiful actress, she only appeared in four Kurosawa films, notably as the prostitute Osen in The Lower Depths (top photo). In Red Beard, she plays a distraught woman, compelled to marry her mother's lover, while they continue their affair, and even bearing his children.
I also have a page on Japanese WW2 movies, none of which are listed here.