The Diary of a Husband serves as an illustration for the arrival of the white-collar economy, in which the extended family is replaced by the smaller nuclear family. It is a story about four pals who work at the same office, which, like other white-collar workplaces, has become the men's primary site of life, where livings are made and friendships fostered. Meanwhile, their wives have fostered something of their own—a brigade to catch cheating husbands. Much comedy is then generated by the cat-and-mouse game between the men and the women...The battle line drawn here between the sexes remains for years, to the extent that this very same story has been retold many times in Hong Kong films, including Men Suddenly in Black, the 2003 Pang Ho-cheung film with a similar Chinese title.

Dirt-poor painter But Ka-sing lives under the same roof with Tang Chan-sin and Lee Tai-hak. Smitten with Tse Mei-chen, the penniless suitor resorts to staging a suicide and makes a fortune of his paintings which are sold at sky-high prices after his feigned death. Reinventing himself as a doctor, But competes with the rich heir Fung Chak-chak to win Tse's heart with an avalanche of gifts and money. However, Tse rejects the suit of the philistine. But gives up his windfall and tells the truth at his memorial exhibition. Thrilled, Tse pledges her love and marries the painter, for better and for worse.