Kamiyama Seiichi (Fukumoto Seizo) is employed at a Kyoto studio as a "kirare-yaku" or "drop-dead" actor: a swordsman extra in samurai films who is always killed off in the fight. For 40 years he has been appearing in this capacity on a continuing TV samurai drama starring the hereditary kabuki actor Onoe Seijuro (Matsukata Hiroki) and, before him, his father (Kobayashi Nenji). At the start of the film, the cast is suddenly informed the show has been cancelled, to make way for a new period drama with younger actors and staff. This new drama uses CG trickery, inauthentic costumes and anachronistic props. Kamiyama and his small cohort of veteran drop-deads scrounge to find new roles at the studio, but disrespect from younger staff relegates them to performing in sword demonstrations for visiting tourists. (There is still a period studio in Kyoto at which these on-set "ninja shows" are done: the Uzumasa of the title.) Kamiyama still practices his swordplay every night on the deserted sets. He is noticed by a young female extra, Iga Satsuki (Yamamoto Chihiro), who convinces him, with difficulty, to take her on as a swordplay pupil. She soon lucks out and is catapulted to stardom as a swordswoman; while Kamiyama, starting to feel his age, is eventually pressured into retirement. When it is decided to co-star Iga with Onoe in a new film for theatrical release based on the 40-year samurai drama, she insists Kamiyama be given a featured drop-dead role, and then must convince a sad and hesitant Kamiyama to appear. The studio is happy to see him back, but in his big fight scene, for the first time in his life, he fumbles his sword. The director (veteran Nakajima Sadao, as himself)) wants to cut Kamiyama from the scene, but the young producer pressures him to take the scene again. In a closely-filmed, spectacular finale fight scene, Kamiyama executes his swan-song with beauty and grace, falling in a shower of cherry blossoms.