At the time this story of feuding 16th century samurai clans was the most expensive Japanese movie ever made (Francis Coppola and George Lucas executive produced and 20th Century Fox financed) and it was critically well-received, sharing the Palme D'Or with All That Jazz, and winning a swag other international festival prizes.
Whilst admittedly it is visually gorgeous with superb production values and breathtaking staging by Kurosawa it is unfortunately mounted on the foundation of a slim story, that of a common thief (Tatsuya Nakadai) who, because of his resemblance to the warlord Shingen (Nakadai) head of the Takeda clan,is groomed as Shingen's double or “kagemusha”. When Shingen is mortally wounded by a sniper in order to maintain morale Shingen’s war council replace him with the double. While the clan’s enemies try to work out if they are being duped the double must withstand the scrutiny of his inner circle including grandson and mistresses not to mention Shingen’s horse.
Kurosawa alternates between the rich elegance of Shingen’s quarters in the formidable Takeda fortress and stylized massed battle scenes in what is a marvellous recreation of the period and an insight into its downfall in the endless struggle for personal power.
The problem with it, one which Kurosawa does not overcome is that his content does not match the grandeur of his vision with too many eye-catching visual tropes - galloping horses charging toward the camera or being brought to a halt in clouds of dust, couriers running frantically down flights of steps, troops marching in formation their flags fluttering noisily in the wind, and so on - being over-indulged. A garishly coloured nightmare sequence is also questionable in this respect. (The original print which ran 181 minutes was cut to 152 minutes for international release).
Even so, as spectacle, Kagemusha is a staggering film.
FYI: Kurosawa would revisit the subject in Ran (1985), a transposition of 'King Lear' to feudal Japan with superlative results.