The Diary of a Big Man

Chow Ting-fat introduces himself with a humorous narration and reveals his dream of wealth and marrying multiple beauties. In a heavy rain, his car breaks down and he seeks shelter, where he meets two alluring women: Joey and Sally. He conceals his intentions while the seed of a two-timing life is planted, setting the stage for the later deception.

Chow quietly commits to two marriages, tying the knot with Sally in Paris and Joey in America, keeping the relationships secret from both wives. The doubles lives begin in earnest as he tries to maintain appearances across distant cities. The double marriage lays the foundation for the impending complications.

To avoid exposure, Chow drafts a meticulous timetable that allocates time for each wife, rehearsing excuses and signals to maintain the illusion. He relies on careful planning, sign language, and rapid cover-ups to keep both marriages from collapsing. The routine becomes his lifeline as the deception tightens.

Sally flies back to Hong Kong to surprise Chow for an early birthday, inadvertently wrecking his perfect plan. The surprise arrival pulls Chow away from Joey and exposes how brittle his schedule has become. The disruption marks the first real crack in his orchestrated double life.

Chow enlists his best friend Chi-hung to act as a backup in emergencies, and the two concoct code signs and evasive excuses to hide the two-timing ruse. Chi-hung's involvement expands the deception but also adds to the mounting pressure. The plan works for a time as threats of discovery loom.

Chow suffers a road accident that lands him in the hospital, triggering Inspector Cheng's suspicions about his two women. The encounter raises the stakes but does not yet reveal the truth. The hospital scene becomes the first test of Chow's ability to dodge exposure.

Chi-hung pretends to be Chow to answer questions from the inspector, deftly deflecting inquiries by claiming there are many Chows in Hong Kong. The inspector leaves convinced there is nothing single out of place, partly fooled by Chow's imposter. The misdirection buys Chow more time but only temporarily eases the tension.

Joey and Sally unexpectedly start to befriend each other, causing the two worlds to collide at Joey's boutique and later at a hair salon. The girls' growing friendship magnifies the risk of discovery as Chow's alibis strain under social proximity. The mounting familiarity heightens the likelihood of exposure.

During the first-year wedding anniversary, the two wives coincidentally meet again and discover their husband is the same man when they spot paired wedding albums. The revelation shatters Chow's control and escalates the emotional stakes for everyone involved. The moment crystallizes the double life into a shared, painful truth.

Angry, the wives plot a vacation and invite the men to a hotel for a Valentine celebration; Chow is unaware of the trap when he wakes up on a bed with both wives tied up. The women deliver a harsh lesson, teaching him through humiliation and a sharp reminder of the consequences of deceit. The failed attempt to woo them back follows this confrontation.

After the hotel fiasco, Chow attempts to woo back his wives, but the effort falls short. He ends up chasing them as they decide to leave and return to Hong Kong, illustrating the collapse of his double life. The pursuit underscores the unsustainable nature of his arrangement.

The police, led by Inspector Cheng, mount a tactical strike against two criminals near the location where Chow first met his wives. The arrival of Chow and his wives near the scene inadvertently gives the criminals an opening to seize the wives as hostages under police scrutiny. The situation tightens the noose around Chow's elaborate deception.

The wives confront the criminals with unexpected boldness, and the criminals, fearing the consequences, surrender to the police. The inspector observes as order is restored, and the danger that once threatened the whole group subsides. The close call marks the final unraveling of Chow's plan.

Chow apologies to his two wives in the rain, admitting that a life with him is untenable. He sends them home by taxi, and they share a sad, resigned look as he walks away into the downpour. The film ends on a somber note about the cost of deceit and the possibility of moving on separately.