柳生源三郎（泽村国太郎 饰）到道场作上门女婿，哥哥对马守（坂东胜太郎 饰）将家传的猴壶送给弟弟作“嫁妆”。源三郎和对马守都不知道，这看似破破烂烂、毫不起眼的猴壶内竟隐藏着百万两银子的秘密。得知真相的对马守急忙派人索要，事感蹊跷的源三郎也渐渐知晓内中原委。然猴壶却被妻子卖给了收破烂的人。 　　猴壶辗转到了孤儿安吉（宗春太郎 饰）手中，他因父亲遭流氓杀害而被射箭场收留，得到女主人阿藤（喜代三 饰）和独臂独眼剑客丹下左膳（大河内传次郎 饰）的照顾。源三郎寻找猴壶途中，偶遇射箭场的美丽少女，于是从此以寻找猴壶为借口，流连射箭场中，更与丹下左膳成为好友……

本片是山中貞雄的遺作，也是他的“時代劇的庶民電影”的代表作之一。他在片中吸取了美國電影和法國電影的影響，並受到摯友兼老師小津安二郎的“小庶民電影 ”美學影響，將歷史上江戶時代的小人物形像注入現代庶民的語言、性格、行止、靈魂，成就了一部難得的社會現實主義的佳作。故事發生於十八世紀德川幕府時代，以悲涼調子訴說德川幕府時期低下層的生活，開頭與結尾都是自殺場景，映照出舊時日本社會草根階層的悲哀。另外，山中的剪輯流暢自如，視覺風格鋒如日本繪畫，演員表演也很自然。此片公認為山中最好的作品，也是他僅存的三部電影之一。 　　Humanity and Paper Balloons,unlike most other Japanese films of this period,is a historical film with a critical edge.Refusing to glorify samurai,the film insteaddeflates the myth around them with a gentle humanity. The film opens directly after a penurious ronin samurai has taken his own life.At his funeral his neighbors from his slum mourn his death. Here the film introduces another ronin samurai who lives in equal poverty. Having pawned his sword for food,the samurai searches for work but to no avail. The family's only income comes from the little balloon children's toys made by the wife.Out of desperation,the samurai abets in an attempted kidnapping. After finding out,the wife kills him in his sleep and then takes her own life, closing the film's narrative circle. 　　Brian Whitener, All Movie Guide.