Aging Kamata movie star "Gin-chan" Ginshiro (Morio Kazama) is filming a story about Samurai in Imperial Japan at the start of the Meiji. Also appearing in the movie, as his antagonist, is rising young star Tachibana (Daijiro Harada). While Tachibana is being filmed, Ginshiro and his crew of bit-player lackeys become upset that Tachibana is receiving more close-ups and more daring scenes. When he takes his turn on camera, Ginshiro overacts and hams up the scenes, ensuring lots of face time on the camera. This desperate attention seeking upsets Tachibana as well as the film crew.
After the shoot, Ginshiro is approached by Makoto (Toshiya Sakai), an adoring young fan, who flirtatiously asks him to sign her inner thigh. Ginshiro charms her, and she giddily thanks him and leaves in her car. Ginshiro, annoyed at his lackeys for not sealing the deal and getting her number for him, enlists his most trusted lackey Yasu (Mitsuru Hirata) to chase after her car and get her number. After a daring and stupid move, Yasu succeeds. But in a mood swing later, frustrated that he is losing popularity, Ginshiro gets drunk at a local bar and, upset at the lack of admiration received from the bar patrons, he goes on a rampage, which Yasu and the other lackeys manage to stop.
Ginshiro visits the cramped apartment of Yasu with his actress girlfriend Konatsu (Keiko Matsuzaka), begging Yasu to marry Konatsu because she is pregnant, and the story could ruin Ginshiro's already waning career. Expressing this fact depresses Ginshiro, who demands Yasu watch as he forcibly has sex with Konatsu.
Yasu agrees to marry Konatsu, partly due to his sense of duty to Ginshiro, but partly because he has been a fan of Konatsu since her first movie. Ginshiro insinuates angrily that it is also because Yasu cannot get a woman any other way.
Ginshiro has an argument with the director of the film over a climactic scene involving Ginshiro fighting off dozens of samurai on a 30-foot staircase; the studio has cut the scene declaring it is too dangerous and no one will play the part of the samurai that Ginshiro victoriously kicking a samurai down the staircase. None of Ginshiro's available lackeys will do it, either, as everyone is afraid such a fall would be fatal.
Yasu takes to the task of providing for pregnant Konatsu dutifully, though Konatsu is unhappy to lose Ginshiro but also feels like a marriage to Yasu is a badge of shame, and chides him for being a weak man. Yasu begins to take on any bit part he can get his hands on, no matter how dangerous, often using the appeal "my girl is pregnant" to justify taking on a full plate of dangerous roles. He uses each little bit of cash to front a number of installment-plan purchases of home furnishings to provide Konatsu with a more comfortable lifestyle, including buying her a bed and opting to sleep in his own closet. Konatsu begins to warm slowly to Yasu. In a gesture of farewell, Konatsu uses her key to Ginshiro's unkempt apartment to clean it up for him, and leaves her key behind.
Meanwhile, Ginshiro is having relationship problems with Mokoto, and asks Konatsu to talk to her and sing his praises, which she tries to do, and flighty young Mokoto returns to Ginshiro's arms, which makes Konatsu uncomfortable. She returns to Yasu, who she decides to devote herself to, bringing him lunch while on the job and taking care of his tiny apartment.
Yasu and Konatsu travel to Kyushu to meet his family, where they are greeted with lots of fanfare. Yasu's family is clearly excited and impressed that Yasu has managed to get engaged to such an attractive and illustrious woman, but Yasu's mother suspects the sham behind the arrangement, and pleads with Konatsu not to break her son's heart. Konatsu retires to the bedroom, where Yasu has been awkwardly trying to decide whether to try to get more intimate with Konatsu. Ultimately, she moves their pillows next to each other, reminding him that they are to be married, and therefore should act like it, and they sleep together.
Returning to Kamata, Konatsu dives headfirst into her future with Yasu, trying to discard her past spoiled actress lifestyle and fully prepares for a dutiful married life with Yasu. However, she visits the Toei set and runs into Ginshiro, who is depressed after losing Mokoto. After reminiscing over their fun-loving past together, Ginshiro puts a Y30M gemstone ring on Konatsu's finger, asking her to marry him instead. Konatsu refuses, stating that she is beginning to love Yasu, and also feels compelled not to disappoint the pleas of Yasu's mother. Jilted, Ginshiro runs off. The scene shifts into Konatsu's happy wedding to Yasu.
Konatsu and Yasu move into a better apartment, and Konatsu takes on the role of a willing wife, having decided that a life with well-meaning and willing Yasu is the best for her and her child. Word gets around that Ginshiro has gone missing, which is holding up production of the film. Yasu, still feeling loyalty to Ginshiro, searches the city to look for him, finally finding his car parked outside an abandoned warehouse. Upstairs, he finds a sulking, depressed Ginshiro, who laments that his star has faded, and expresses a wish that his career end with a bang -- the dangerous staircase scene. Yasu offers to take on the dangerous role of the samurai who falls down the huge staircase, partly out of devotion to Ginshiro, but also sees a way to use the opportunity to provide handsomely for Konatsu.
The studio director, thrilled at Yasu's offer, gets him Y1M in hazard pay; meanwhile, Yasu arranges for a Y100M insurance policy on himself, expecting that the chance of him dying in the stunt will result in a payoff for those he loves. He includes both Konatsu and Ginshiro as beneficiaries. Konatsu, however, does not want Yasu to take on such a dangerous stunt and possibly die. As his sense of selfless generosity and the demands of bit playing and the stress of his devotion to both Konatsu and Ginshiro take its toll, he starts falling apart, handing out pieces of the insurance payoff to all his fellow bit players, taking advantage of the risky plan to gain friends and respect. After he brings home a horde of random strangers (all of whom have become beneficiaries of his insurance policy) and invites them to eat Konatsu's dinner for him, she angrily kicks them out, and begins to beg Yasu not to do the scene. He has a nervous breakdown and begins violently trashing everything in the apartment, while Yasu pleads with him to calm down. He rants in spite about everything including the difficult position of raising a child that isn't his, something he didn't mind at first. After recklessly hitting her, he crumbles, and begins to simper about the pressures of the movie industry, in which he does "everything my superiors ask of me" without much in return, and expresses his frustrations with his life, and how his increasing love and devotion to Konatsu weighs on his emotional state. Ashamed, he leaves to go to the set, leaving a heartbroken, still devoted Konatsu behind.
The next day, Konatsu packs up and leaves to go to the hospital; meanwhile, Yasu goes to the set, having finally given up all self worth. He refuses to eat before the shoot. Preparing for the scene, he takes advantage of everyone's amazement and respect at his role, acting like a diva, even getting Tachibana to light his cigarette, and angrily railing against the studio executives who have personally arrived to watch the dramatic scene.
With her baby not yet ready to be delivered, Konatsu leaves the hospital and walks to Toei Studios, hoping for another chance to stop Yasu from doing his dangerous stunt. Meanwhile, the studio starts the scene. Ginshiro, playing the antagonist Imperial Guard, marches up the staircase with his men, dispatching a team of samurai, led by Yasu, every few steps, Near the top, Ginshiro and Yasu fight, and Yasu, true to his proud job as a bit player, tumbles recklessly down the stairs. Broken and bleeding, he weakly recovers, and begins crawling back up the stairs. Ginshiro cheers him on for his extreme devotion to the scene; eventually he runs out of steam, and tumbles back down. Outside, Konatsu watches as medics load Yasu into an ambulance; at that moment, Konatsu's water breaks.
Konatsu wakes in the hospital, hearing her baby crying for her. She hears Yasu's voice, but refuses to open her eyes, fearing his voice may be a dream. She opens her eyes to find Yasu, heavily bandaged, doting over her; they can all live happily ever after now. Just then, the hospital room walls are pulled apart, revealing it is a small set built on the same soundstage as the huge staircase, surrounded by the movie cast and crew, celebrating the end of the movie, a sendoff to the story's original beginnings as a stage play.