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.

Lee Kei-hau is happily married with a son. His wife Wong Tai-chu, who has been complaining of discomfort lately, goes to see a doctor where her friend Wong Mau works as an assistant. Wong mixes up her report with that of a cancer patient. Believing her days are numbered, Tai-chu discusses with her mother to choose a second wife for Lee and finds the nurse So Lin-yung, Mau's girlfriend. Mau feels obligated to adhere to her request to hire So as family nurse. Lee urges his wife to make regular exercise a habit to improve her health but when his advice falls on deaf ears, he spurs her to action by dating the nurse. Infuriated by his wife's unexpected exhilaration, Lee accuses her of having an affair with Mau. Tai-chu retaliates by displaying great affection towards a man, her girlfriend Judy in disguise. Lee chases after the beau relentlessly and is told the truth by Judy. Mau's blunder is patched up with a smile, for his lover So, and for the reconciled couple Tai-chu and Lee.

Entrepreneur Silly Wong returns from overseas having made a fortune there. His godson Tsim Tsui-mau and wife Ho Bit-siu, and friend George Cheung use every trick in the book, even hiring the alluring singer Lin Yung-so, to entertain and curry favour with the loaded returnee. Unfortunately Wong's saving, totalling 10 million dollars, is only due to arrive in two weeks. Penniless, he remains evasive over financial matters. Tsim thinks that Wong is a swindler and leaves in a fit of anger. Lin gives him a hand in his moment of need, and love blossoms between them. Mau and others believe that Lin must have gathered evidence of Wong's wealth and thus forcibly take him home. Realising Tsim's snobbishness, Wong admits to a fuming Tsim that he a broke man. Finally the money arrives. Wong cherishes Lin's love and marries her, but shows the door to the remorseful Tsim and friends.

Yim Tai-hung stages a diamond heist but one of his men slips away with a diamond necklace. Sustaining a fatal wound, the betrayer gives the necklace to his friend Chow Ping at Rose Apartment before he expires. Chow calls her cousin Wu Nga for help. But Wu, Wong Ang and Heung At come too late. She however manages to reveal the whereabouts of the necklace at her last breath. The trio is framed for the murder but is later acquitted. Striving to crack the case, Wong infiltrates the apartment at night and uncovers the necklace, which is then used to lure the real culprit out. But her plan is foiled by a young and reckless Wu who falls into Yim's trap. Luckily Wong and Heung deliver the hostage to safety while the police arrest Yim's accomplices and kill the ringleader in the ensuing shootout.

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.

During the Warring States Period, Nung-yuk, the Princess of Qin, denounces the mundane world and dreams of marrying an immortal. This extends to her criteria for choosing a husband: excelling in flute playing. Once, she is captivated by the tune 'Three Melodies of Rainbow Dress' and mistakes the qin player Siu Sze for a fairy. Yuk then persuades Sze to sit the national exam for a better future. Sze's music attracts hundred of birds. Yuk returns to the palace pleading with her father Esquire Muk to agree to their marriage. Despite the Empress Dowager's opposition, Yuk leads a secluded life with Siu afar; a noble breed thus living a hard life. The King lets her go, only granting an annual visit. A year later, Yuk and her husband returns for a visit. The Queen still wants to break them up. Later, Jin State sends people to discover the whereabouts of their Princes. Siu is in fact the Prince of Jin. With Muk’s blessings, Siu marries Yuk in Jin, a marriage which brings peace to both states.

Scholar Yuen Man-lung leads a double life as Vigilante Golden Cat. Yuen is separated from his lover Tso Oi-lan by her snobbish father who promises her to Tsui Tai-fei, son of the magistrate and incriminates him as the wanted burglar. Yuen sneaks out of prison and wreaks havoc in Golden Cat's name; the exasperated magistrate has to release him. Before leaving for the imperial exams with the runaway Oi-lan, Yuen stages one final heist for his friend's sake. The officials trail Golden Cat to his house where his nocturnal costume is retrieved. His father is arrested as the criminal. Drawing a plan up her sleeves, Oi-lan's sister Oi-ling whisks the elder out of the execution ground. Despite failing at the exams presided over by corrupt examiners, Yuen saves the emperor on his homecoming journey, and returns triumphant as a duke.

On his way to Lin'an, Lee Tsi-wan survives an attempt on his life by an employee but loses his memory. Maid Siu Yuet-mui of the Sek family comes to the help of the distressed. Lady Sek marries Siu to Lee to vanquish her husband's licentious interest in the maid. The loving couple raises a daughter Siu-fa. A few years later, Wan is hit on the head away at work and regains his memory. The homesick traveller returns to his native home, leaving behind Siu and daughter. The mother and daughter look for the missing man but he hasn't the faintest idea who they are. Apprehended by the incident, Siu plunges into depression. One day, Lee passes by the stone house where the couple used to live in and recalls past episodes of his marriage. The family is happily reunited.

The Prime Minister's daughter, Kong Yeuk-mui, is attracted by the private tutor, Chow Yuk-pui. However, the Prime Minister despises Pui's lowly background and banishes him. Kong disowns her father, hoping to marry Pui when he achieves honours in the imperial exam. Meanwhile, Mui's brother Tak-chu prepares for the exam under Pui's tutorship. Pui and Chu, take the money Mui gives them and head for the capital. Unfortunately, Pui has himself fallen ill. Considering that the examination day is approaching, he gives all the travel expenses to Chu and urges him to set off. Mui resides at Loquat Alley, longing for Pui's honourable return. One day, she comes across a beggar, when she recognises it is Pui, her heart breaks. Chu who has newly been appointed Top Scholar, arrives and tells her sister the whole story. Nevertheless, Pui's sister is chosen to be the imperial concubine. Benefiting from this bond, Pui becomes the Royal Brother and works as the court secretary and weds Mui.

Chan Kwai-sheung visits the brothel with So Tung-bo while his wife, Lau Yuk-ngo, is sleeping. As this is the first time Sheung did this, Ngo wants him to suffer and so makes him wear a lamp on his head. During the Lantern Festival, the Emperor has fun with his officials. After a few drinks, Bo says that Ngo has lost the virtues of a woman. Ngo immediately appeals to the Emperor. All the women there, including the Empress, say that Bo should be punished. Bo is unhappy and invites his cousin, Kam Cho, seduce Sheung to make Ngo unhappy. Sheung, a philanderer, schemes to take Cho as his concubine. Ngo finds out and beats him. Bo urges Sheung to divorce Ngo. Ngo is furious and lodges a complaint with the imperial court. The Emperor allows Sheung to have a concubine. Ngo pleads that she would rather drink poison than let Sheung take a concubine. Feeling remorseful, Sheung drinks the poison after his wife. Fortunately, the queen has switched the poison with vinegar. The couple reconciles.