Nobita Nobi is a fourth-grade student living in Tokyo as an only child. His significant underachievement creates financial hardship for his descendants in the 22nd century. This future consequence leads to the intervention of Doraemon, a robotic cat sent back to guide Nobita toward better choices and lessen the future impact on his family.

Nobita struggles academically, performs poorly in athletics, and generally lacks motivation, often appearing timid and unmotivated. He experiences frequent failures in everyday situations, earning him a reputation for chronic bad luck. Despite these shortcomings, his attempts to overcome his limitations frequently drive the story forward throughout the franchise's media. This includes the original manga, television adaptations from 1973, 1979, and 2005, and numerous films and specials. Specific seasonal stories, like the summer special "Doraemon: It's Summer!", show him in seasonal activities and adventures consistent with his core traits.

He heavily relies on Doraemon's futuristic gadgets, though his misuse or the gadgets' inherent flaws often worsen situations, causing complications instead of solutions. Interactions with peers, especially the bullying Takeshi "Gian" Goda and the boastful Suneo Honekawa, contribute to his recurring troubles. Despite frequent setbacks and a tendency to avoid challenges, stories across films, episodes, and specials sometimes show moments of perseverance or concern for others. However, these moments do not fundamentally change his established personality. His experiences cover diverse scenarios, including historical journeys, space exploration, fantasy realms, and everyday problems, all framed by his constant struggle against personal limitations and external pressures.