Doraemon is a male cat-type robot from the 22nd century, specifically manufactured on September 3, 2112, at the Matsushiba Robot Factory. His original design featured a yellow color and a set of ears, and he was painted using an egg-based paint. The origin of his name combines "dora," which is derived from "dora neko" meaning stray cat, with the traditional Japanese suffix for male names, "-emon". He stands 129.3 centimeters tall and weighs 129.3 kilograms, dimensions that are a recurring theme in his specifications.

The most defining event in his personal history is the loss of his ears. While resting, his ears were gnawed off by a mechanical mouse. This led to a series of traumatic events: a subsequent surgery to remove the remnants left him bald, which caused his then-girlfriend, a cat named Mii-chan, to laugh at him. In a state of deep sadness and depression, he accidentally drank a potion designed to induce sorrow. His crying was so intense that the yellow paint covering his body washed away, revealing the iconic blue undercoat that he is known for today. This backstory explains his two most prominent characteristics: his blue, earless appearance and an intense, almost phobic fear of mice and rats.

As a robot, Doraemon is equipped with several physical features. His most notable asset is the four-dimensional pocket, or fourth-dimensional space pocket, located on his abdomen. This pocket serves as a storage unit that connects to another dimension, allowing him to carry a vast array of futuristic gadgets, known as "secret tools," of virtually any size. His other features, such as a highly sensitive nose, radar whiskers, and a bell used to summon cats, have often malfunctioned and are no longer reliably functional, marking him as a substandard model in some respects. A red tail serves as his main power switch; if pulled, his operating systems will shut down completely. His favorite food is dorayaki, a sweet red bean pancake, for which he has a very strong fondness.

In terms of personality, Doraemon is fundamentally kind, patient, and possesses a strong sense of responsibility. He has a gentle disposition but also displays a practical and sometimes exasperated side, particularly in response to the repeated mistakes and poor judgment of the boy he is tasked to help, Nobita Nobi. Despite his advanced technology, he is not infallible. He can be careless when rushed, sometimes leading to unintended chaos with his gadgets. He has a distinct unrequited affection for a local cat named Mii-chan, occasionally neglecting his duties for her, though not to a detrimental degree. He becomes enraged when mistaken for a raccoon dog, which is a common gag due to his earless appearance. He is also sensitive about his lower-quality status compared to other robots, such as his younger sister, Dorami.

His primary motivation and overarching mission is to help Nobita Nobi, a pre-teen boy who struggles academically, is often bullied, and lacks motivation. According to the original backstory, Doraemon was sent back in time by Nobita's future descendant, a boy named Sewashi, to improve the ancestor's fortunes. Sewashi reasoned that Nobita's personal failings were causing great hardship for his entire family line in the 22nd century. Doraemon's role in the story is to act as a surrogate older brother, guardian, and problem-solver, using his future technology to guide Nobita toward a better future, though his efforts are often complicated by Nobita's misuse of the powerful gadgets or his own flawed decision-making. This mission places him at the center of almost every adventure, during which he works to correct Nobita's immediate troubles while subtly encouraging personal growth.

His key relationship is, without question, with Nobita, a bond that is complex and deep, moving beyond a simple guardian-ward dynamic into a genuine and enduring friendship. He also has a close, though often behind-the-scenes, relationship with his sister, Dorami, who is a more advanced and higher-quality robot. He interacts regularly with Nobita's friends and classmates, including Shizuka, Takeshi "Gian" Goda, and Suneo Honekawa, often mediating their conflicts or rescuing them from predicaments.

Doraemon's most notable abilities are entirely derived from the contents of his four-dimensional pocket. Among the countless futuristic tools he can produce are the Bamboo-Copter, a small propeller that can be placed on the head to enable flight; the Anywhere Door, which can transport its user to any location upon command; the Time Machine, which is typically kept in Nobita's desk drawer; and the Time Cloth, which can turn objects to either an older or newer state. His personal physical abilities include hands that can stick to objects and a functional atomic furnace that converts eaten food into energy. A well-known running gag is his extreme fear response to seeing a mouse, which compels him to jump to a height of 129.3 centimeters and run away at a speed of 129.3 kilometers per hour.