Genjuro and Tobei are neighbors and brothers living outside the town of Nakanogo in early 16th century Japan, "a time of civil war". They are both farmers, but Genjuro also has a pottery business that his brother assists him with. Genjuro has the standard dreams of a peasant, to be richer and more successful, while Tobei has ambitions to become a samurai. Genjuro's wife Miyagi fears that his greed will bring harm to them and their son Genichi, while Tobei's wife Ohama finds his samurai dreams ridiculous.
Rampaging soldiers from the army that just lost the war force the two brothers and their family to flee. After the soldiers move on Genjuro returns to his home and is delighted to find that his pottery is intact. They set out across the lake to Nakanogo to sell Genjuro's wares, believing that route to be safer than overland with soldiers on the loose, but on the way they find a dying man in a boat who warns them of pirates, before he croaks. Genjuro returns Miyaki and Genichi to shore despite her objections, and the brothers then push on across the lake with Ohama. This decision eventually leads to disaster for both couples, but not before Tobei gets a chance to act on his samurai dreams, and not before Genjuro meets a strange, bewitchingly beautiful noblewoman, Lady Wakasa (Machiko Kyo).
- Almost Dead Guy: Genjuro and his family are crossing the lake when they see a drifting boat. It contains a grievously wounded man who warns them that there are pirates on the lake. He then dies.
- Better to Die than Be Killed: A defeated general has his underling lop off his head. Tobei stumbles onto this scene, kills the underling, and makes off with the head.
- Bittersweet Ending: Miyaki is dead, but Genjuro has gone back to his pottery and raising his son, while Tobei leaves the samurai life behind and brings his wife home. The original script had a more Downer Ending in which Tobei leaves his wife in prostitution and goes off to enjoy the life of a samurai, but Executive Meddling led to a happier resolution for that subplot.
- Blatant Lies: Tobei does a lot of bullshitting about how to become a samurai, when in truth he became a samurai by stealing a severed head.
- Boy Meets Ghoul: Genjuro's lover, Lady Wakasa, turns out to be a ghost seeking the love that she never found in her short mortal life.Genjuro: I never knew such pleasure existed!
- Cute Ghost Girl: Lady Wakasa turns out to be more of a "scorching hot ghost girl."
- Dead All Along: It's actually not all that surprising when the rather spooky, slightly Uncanny Valley-ish Lady Wakasa is revealed to be a ghost. It's much sadder when Genjuro wakes up the morning after coming home to Miyaki, and finds out that she is a ghost as well.
- Decapitation Presentation: Tobei steals the head of the dead general, makes his way to the court of the victorious general, presents the head, and demands to be made a samurai for killing the enemy leader. No one believes him, but they make him a samurai anyway.
- Defiled Forever: How Ohama feels about herself after she's raped. She becomes a prostitute.Ohama: I'm a defiled woman, and you're to blame!
- Double Standard: Rape, Divine on Mortal: It's actually ambiguous whether Lady Wakasa simply seduced Genjuro by being really sexy, or if she used supernatural powers to bewitch him. But if she bewitched him, then basically you have a ghost raping a mortal, and it's portrayed as tragic rather than evil.
- Easily Forgiven: Played with. It seems like Miyaki is awfully welcoming to Genjuro after he comes home, what with his long disappearance and her suffering. Then the morning reveals the situation to be completely different.
- Epic Tracking Shot: Mizoguchi is known for them, and there are several here, notably the opening scene where the camera goes swooping across the countryside to find Genjuro and Tobei at work.
- The Film of the Book: Based on two stories from the book Ugetsu Monogatari: "The Lust of the White Serpent" (a demon seduces a man), and "The House in the Thicket" (a man comes home to find the ghost of his wife).
- Greed: Miyaki notes that she cares about Genjuro's attention more than the finery he buys her when his pottery sells. Later she says that his workaholic behavior is driving them apart.
- Hope Spot: Miyaki is stabbed in the back by a soldier turned bandit, and collapses. The narrative leaves her behind for quite a while, until Genjuro comes home to find Miyaki, who welcomes him back with open arms. It seems as if they're happily reunited, until the next morning, when Genjuro finds out that Miyaki is dead and he saw a ghost.
- Jidaigeki: Specifically, the Sengoku Period, which was in fact a time when Japan was riven by warfare.
- Ominous Fog: The waters of the lake are still, but bound thickly with fog as Genjuro and his party cross. Soon they find the dying guy in the boat.
- Protective Charm: A Buddhist priest tells Genjuro that Lady Wakasa is actually a ghost, and then scrawls some Buddhist prayers on Genjuro to keep her away from him. Sure enough, when Lady Wakasa sees the characters drawn on his back, she recoils.
- Rape Discretion Shot: As the soldiers throw Ohama down and gag her, the camera pans away to her shoes, still lying in the dirt where the soldiers first jumped her.
- Sexy Discretion Shot: In one of the more famous shots in the film, Lady Wakasa takes her clothes off (offscreen, but we see the clothes on the ground) and gets in a natural pool to make love to Genjuro. The camera then pans away to a trickle of water running away from the pool—and finds the two of them having a picnic in a meadow.
- Untranslated Title: "Ugetsu Monogatari" translates out to "Rain-Moon Story".
- War Is Hell: A running theme, and typical of Japanese cinema just eight years after World War II. Rampaging soldiers bring devastation to Genjuro's village. They rape Ohama and kill Miyaki.