For young Parisian boy Antoine Doinel, life is one difficult situation after another. Surrounded by inconsiderate adults, including his neglectful parents, Antoine spends his days with his best friend, Rene, trying to plan for a better life. When one of their schemes goes awry, Antoine ends up in trouble with the law, leading to even more conflicts with unsympathetic authority figures.

Now aged 17, Antoine Doinel works in a factory which makes records. At a music concert, he meets a girl his own age, Colette, and falls in love with her. Later, Antoine goes to extraordinary lengths to please his new girlfriend and her parents, but Colette still only regards him as a casual friend. First segment of “Love at Twenty” (1962).

The third in a series of films featuring François Truffaut's alter-ego, Antoine Doinel, the story resumes with Antoine being discharged from military service. His sweetheart Christine's father lands Antoine a job as a security guard, which he promptly loses. Stumbling into a position assisting a private detective, Antoine falls for his employers' seductive wife, Fabienne, and finds that he must choose between the older woman and Christine.

Parisian everyman Antoine Doinel has married his sweetheart Christine Darbon, and the newlyweds have set up a cozy domestic life of selling flowers and giving violin lessons while Antoine fitfully works on his long-gestating novel. As Christine becomes pregnant with the couple's first child, Antoine finds himself enraptured with a young Japanese beauty. The complications change the course of their relationship forever.

Antoine is now 30, working as a proofreader and getting divorced from his wife. It's the first "no-fault" divorce in France and a media circus erupts, dredging up Antoine's past. Indecisive about his new love with a store clerk, he impulsively takes off with an old flame.