Lan Kwong Film Company

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.

In order to wait for her lover Fan Chun-tak to finish his study in Australia, Tang Sau-man works as a governess in Chui Shek-wah's house. Chui is Fan's brother-in-law. Chui spoils his wife Fan Kam-ping. She becomes lazy and dependent on Tang. Fan finishes his study and returns. He decides to transform his elder sister. He asks her best friend, Pang Shui-ha, to persuade her. Pang has a crush on Fan. Pang uses this opportunity to get intimate with Fan. Tang originally thinks that after Fan comes back, she no longer has to live in somebody's shelter. But Fan spends all his time with Pang. Tang is unhappy and drinks to vent her unhappiness. Tang gets drunk and Chui takes care of her. However, Ping thinks that they have dubious relationship and throws Tang out. Tang falls down a slope and loses one leg. Fan is angry with himself and decides to marry Tang. Ping also realises that she is wrong. She decides to change her lazy character and takes care of the disabled Tang.

The Lok's family disperses when Japanese occupied China. Mrs. Lok's company prospers in Hong Kong. Her son Tin-yam looks after her business. She misses her daughter. Another daughter Chui-yin dates Kuk-tat. Mrs. Lok hopes that Tin-yam will find a good partner. Wan Yuk-yin works in Mrs. Lok's company and meets Tin-yam. They fall in love. Mrs. Lok asks Yuk-yin to leave Tin-yam. Facing his mother's objection, Tin-yam falls ill. Mrs. Lok let them marry. The wedding guests despised the bride, which makes Mrs. Lok uncomfortable. The couple lives happily, but Mrs. Lok and Chui-yin make Yuk-yin embarrassed. Kuk-tat covets the Loks' fortune. He steals their jewels. Mrs. Lok thinks Yuk-yin did it. Yuk-yin is innocent, but she is expelled. Tin-yam returns. Yuk-yin's parents seek justice at the Loks. Mrs. Lok's saw the Yuk-yin's birthmark. She realizes Yuk-yin is her lost daughter. Mrs. Lok decides to be a dutiful mother. Tin-yam is an adopted son of the Loks so the couple lives happily.

Tang Wan-tung, the son of a Southeast Asian Sultan is a student in Hong Kong. Only Uncle Mui, his guardian, knows his identity. Tang is known as "student prince". He organises an embassy variety show. Tang invites Lai Tsi-king, who has a lovely voice, to perform in it, but it ruins her chance to study music abroad. Lai’s parents want her to marry Tung Fook-si, the son of a merchant. Lai asks Tang to act for her parents, like a prince courting her. Her parents are convinced, but Tung is not fooled. Tang smuggles Lai out to perform in the embassy. Lai's performance earns her a chance to study overseas, but her parents will not support her. Tang borrows money from his father, but is refused. He pawns his father’s ring to help Lai pay the tuition. Tung takes his father's ring and sells it. Tung's father alerts the police. The rings turn out to be a pair. The police think Tang stole the diamond ring, but Mui tells the truth. Tung is arrested and Tang and Lai have a happy ending.

Yuk Yin's father dies and her mother remarries to settle the debts. Yuk Yin lives with Auntie Wong. From then on, Chi Hung, Auntie Wong's son and Yuk Yin live and play together. But the Wongs move away. Yuk Yin stays with her mother. Her stepfather is mercenary. When Yuk Yin grows up, he pushes her to get married to get money. Considering her daughter's future, Yuk Yin's mother sends her away. Yuk Yin works in a restaurant. When she learns that her mother is ill, she marries a dying rich young man to get money for her mother's treatment. After her mother's death, Yuk Yin gets married immediately, but her husband dies on the wedding night. Her mother-in-law sees this as unauspicious and expels Yuk Yin. Later, Yuk Yin chances upon Chi Hung. They are still in love. They married and have a son Kwok Wah. But Chi Hung dies. Yuk Yin works as a dance girl to support their living. Kwok Wah grows up and cannot accept his mother's job. But soon he understands that she is respectable.

Pak coek gung's family rents the third floor of a tenement building. Due to the water shortage, Pak's porridge stall is difficult to operate. At that time, Ah Seng, the son of Pak, owed money to Cheung, the fat man downstairs. Cheung saw that the porridge stall could not operate, so he took away the license of the porridge stall. In order to get the license back, Pak's daughter Miuying had to work as a dancer to pay off the debt. Then Pak's neighbors helped the porridge stall reopen and even reported Cheung for wasting water.

Tong Siu-wah is jobless. Tong shares a room with Chi-on. His neighbour Lai-ping is a factory worker. Another neighbour Siu-kuen is Manager Chin's mistress-to-be. Siu-wah never bumps into them. Siu-kuen is forced to be a mistress to pay back her family debts. Chin is about to marry Siu-kuen as his mistress. Lai-ping and Siu-kuen are friends and Lai-ping wants to help her. Lai-ping and Siu-wah have never met and they argue. Lai-ping separates their rooms, Siu-wah's glass frame was accidentally shattered by Lai-ping. Lai-ping meets her penpal and find out that Siu-wah him. They teach each other to trick their flatmates. Lai-ping puts a fake snake in his room. Siu-wah puts pins on her bed. The two eventually realized who each other is. Lai-ping helps Siu-kuen pay off her debt and not marry Manager Chin. Chi-on discovers that his boss' husband is Siu-kuen's husband-to-be. Chi-on reveals the truth to Mrs. Chin. Chin cancels the marriage. Lai-ping and Siu-wah become a couple.

Lam Siu-ming cannot afford tuition and quitted school. His teacher Ms. Chui intercedes with the principal in vain. She quits. Chui became an orphanage director. She suffers from the orphans’ mischief, but she treats them with love and honesty instead of punishing them. She gets recognition from kids and colleagues. Siu-ming is expelled. He dares not go home and lives on pickpocketing with street boys. Chui learns that Siu-ming is missing and looks for him. Siu-ming feels ashamed and avoids her. Chui finds Siu-ming and takes him and the street boys to the orphanage, yet they cannot be disciplined and escape. Little Bully runs after them, but is beaten down on the railway. Siu-ming's legs are cut off by the train when he tries to save Little Bully. The escaped kids regret for this. Chui's cousin wants her to go abroad together, but at the farewell party, he is moved by the orphans, so he does not force the plan, and decides to stay behind to serve the kids.

A fortune-teller tells Ng Sze-tak that his days are numbered. His friend Chu Tai-fat is told that he will soon win a lottery. Soon, Chu's prediction comes true. Ng lives his days in terror until he realises that everything is but a false alarm.