The story is set in the Edo-period, in a quarter of Tokyo where the poor live in tenement houses. The ramshackle houses stand on both sides of an alley that can be closed off with a gate. Impoverished, masterless samurai (ronin) live here among equally poor people of lower social classes.
The film starts very dark: a masterless samurai living in one of the houses has committed suicide by hanging himself - he had already sold his sword, so harikiri (seppuku) was out of the question. The residents of the tenement houses talk their landlord Chobei into providing some sake during the wake, so they have quite a party. But the merrymaking also serves to cleanse the tenement quarter of lingering evil influences.
One other ronin, Unno Matajuro (Kawarasaki Chojuro), is trying to find work by approaching an acquaintance of his deceased father (a samurai official called Mori, who was once helped by his father), but each time the official who knows neither giri nor ninjo, deftly evades him. His wife, Otaki (Yamagishi Shizue), makes paper balloons at home to earn a few coins. Unno keeps aloof from the others living in the slum and he never touches sake - there is a hint that his downfall had something to do with his previous excessive love of the intoxicating nectar.
Next door lives Shinza the barber (Nakamura Kanemon), a lusty but naive fellow who is constantly harassed by the local yakuza because he runs a gambling joint in what they consider as their territory.
Shinza is not the only one who has yakuza troubles: the upright citizens of the town, such as the merchants, frequently use the services of the gang to beat up bad customers or unwelcome visitors - also Unno Matajiro falls victim to their fists when he follows the samurai official Mori to the premises of a money lender, Shirakoya.
The usurer gets his deserts: his daughter Okuma is to be married to a party introduced by the samurai, but she is in love with her father's clerk, Chushichi. One rainy night, when she is planning to elope with the clerk, she crosses the path of Shinza, who is more penniless than ever. Shinza impulsively abducts her, demanding a ransom from her rich father. When the yakuza come looking for her, he hides her at Matajuro’s home.
But the desperate ransom attempt backfires and the crafty landlord has to sort things out with her father Shirakoya and the samurai official Mori, who was arranging a marriage for her. Okuma is returned to her parent's home and as after this experience she is not suitable for a samurai anymore, she is allowed to marry Chushichi.
She is the only one for whom the story ends happily. This time, Shinza does not get away with it and he is killed by the yakuza boss Yataguro because of the loss of face he has caused him (by hiding Okuma when the yakuza came searching for her). And the poor ronin and his wife, after the umpteed futile attempt to approach the samurai, commit suicide - by killing themselves with a small knife. The last image of the film is of one of the paper balloons the wife has made, blown away by the wind and rolling in the gutter...
Director Yamanaka Sadao was one of the talents of the 1930s, the first "Golden Age of Japanese Cinema," when also Ozu, Naruse, Mizoguchi and Shimizu were going strong. Unfortunately, he died a year after making Humanity and Paper Balloons - he was drafted into the army and sent to Manchuria were he died of dysentery. In his short life, he made 24 films, of which only three survive (besides the present one, The Million Ryo Pot and Kochiyama Soshun).
Yamanaka's films have been highly praised by critics as Sato Tadao and Donald Ritchie for the focus on delineation of character, the blurring of genre lines (between samurai films and modern stories, and between comedy and drama), and the focus on average people. And of course for the cinematography that beautifully captures the claustrophobic nature of the slum in which the story is set on the one hand and that on the other hand cuts away from scenes of violence, only hinting at them (we see the yakuza ominously stamping their feet and unsheathing their swords when about to kill Shinza but then the film cuts to another scene). Yamanaka laid the groundwork on which Kurosawa's films such as Yojimbo became possible. Even in recent times directors continue to pay tribute to him, such as Koreeda Hirokazu in Hana, the Tale of a Reluctant Samurai (2006).
Some cultural points:
- Ninjo is human feeling that complements or opposes giri, or social obligation. Ninjo in the film is the poor helping each other, or in a wider sense, humaneness or humanity.
- Paper balloons were made by gluing strips of colored paper together. As they contained no gas, they would not fly, but were a toy for children. In the Edo-period, they were made popular by the itinerant medicine vendors from Toyama, who used them as presents to customers.
- The sword was the "soul of the samurai." So selling it, was the lowest level of disgrace one could sink to - but that is what utter poverty did to people. Usually, such a samurai would carry a bamboo sword and dagger to hide his shame. In Harakiri (1962) by Kobayashi Masaki a ronin is cynically forced to commit suicide with just such a bamboo weapon.
- These historical epics without sword fights were called "modern films with chonmage." Chonmage is the traditional haircut of the samurai, a shaved pate with the remaining hair bound in a topknot.
- In the 1930s in Japan, many films were made that commiserated with the plight of the poor - and not only by leftists. Even the first war films were not the victorious epics one would expect, but rather films showing how the average people and ordinary soldiers had to suffer.
- Yamanaka did not use normal film actors, but all roles are played by members the Zenshinza Theater group.
- Part of the story is based on the Kabuki play Shinza the Barber by Mokuami Kawatake.
- The first jidaigeki (historical film) about ordinary people and without swordplay, was made in 1928 by Kinugasa Teisuke (Crossroads, "Jujiro").