In a typical suburb of Tokyo, a clumsy, unlucky, and academically hopeless fourth-grade boy named Nobita Nobi lives a life filled with misfortune. He is regularly late for school, scores zero on his tests, is bullied by his classmates, and is frequently scolded by his mother. His bleak present, however, is just the beginning of a much larger problem. Nobita's personal failings are so catastrophic that they have cursed his future descendants with a life of crushing poverty. To alter this disastrous timeline, a young descendant named Sewashi travels back to the 20th century from the 22nd century. He brings with him a special robot: a blue, earless, cat-like caretaker named Doraemon.

Doraemon is sentient, kind-hearted, and possesses a powerful, seemingly limitless tool: a four-dimensional pocket on his abdomen. From this pocket, he can produce an endless variety of futuristic gadgets, known as "secret tools," which he uses to help Nobita navigate his daily struggles. These range from the iconic Anywhere Door, which allows travel to any location, to Bamboo Copters for flight, and Memory Bread, which imprints information onto a slice of bread that can be eaten for instant recall. Despite his good intentions, Doraemon's interventions often backfire due to Nobita's impulsive and lazy nature, creating even more complicated and humorous problems than the ones they set out to solve.

The series centers on Nobita's daily life and his relationships with a tight-knit group of classmates. His closest friend and romantic interest is the kind, intelligent, and gentle Shizuka Minamoto, who often serves as the voice of reason and is fated to become his future wife. Providing constant antagonism are Takeshi Goda, the strong and quick-tempered local bully known as Gian, and Suneo Honekawa, the wealthy, fox-faced, and cunning braggart who is often forced to go along with Gian's schemes. While Gian terrorizes the neighborhood with his terrible singing voice and habit of "borrowing" other children's toys, and Suneo flaunts his possessions, they are not purely villains; they frequently join Nobita and Doraemon on grand adventures, showing loyalty in times of genuine crisis.

The narrative structure is largely episodic, with each episode focusing on a specific problem that Nobita faces, such as a difficult test, revenge from Gian, or a desire to impress Shizuka. Doraemon will produce a gadget from his pocket to solve the issue, leading to a moral lesson about responsibility, hard work, and the consequences of taking shortcuts. However, the series also features notable recurring narrative arcs, most prominently the long series of annual feature-length films. In these films, Nobita and his friends use Doraemon's gadgets to travel to fantastical worlds, such as the dinosaur age, the far reaches of space, or undersea kingdoms, where they confront world-threatening villains and must rely on courage and friendship to save the day. These adventures expand the universe beyond the suburban setting and represent a shift toward high-stakes action and drama. The franchise was rebooted into a new long-running series beginning in April 2005, which continues to adapt the classic stories with updated animation and voice actors, introducing the timeless dynamic of an unlucky boy and his robotic cat from the future to new generations.