Nobita Nobi is a ten-year-old Japanese schoolboy living in Tokyo's Nerima Ward, characterized by significant flaws and emerging strengths. Academically, he consistently fails, often scoring zero on tests and arriving late to class. His athletic abilities are notably poor, marked by low endurance and coordination that frustrates peers during sports. Habitual laziness and procrastination define his routine: napping after school leads to unfinished homework and late nights, worsening his academic struggles and drawing regular reprimands from his teacher and disappointed parents, especially his mother. He sometimes tries, unsuccessfully, to hide bad grades. Nobita exhibits dependency, frequently pleading with Doraemon for futuristic gadgets to solve immediate problems, usually related to seeking revenge on bullies, impressing Shizuka, or gaining material possessions.

Despite these shortcomings, Nobita possesses redeeming qualities. He shows kindness toward animals, often aiding strays, and compassion for others in need. His most notable strength is exceptional creativity and unconventional problem-solving. He frequently devises innovative uses for Doraemon's gadgets beyond their intended purposes, like transforming "power of wind" fans into free-flying equipment or using the "voice hardener" for transportation. This creativity extends to artistic pursuits, including crafting intricate string figures and composing multi-page manga stories despite poor drawing skills. He also demonstrates remarkable marksmanship with projectile-based gadgets. In critical situations, particularly during full-length films, he exhibits unexpected courage, risking his life to protect communities, individuals, or civilizations, revealing a capacity for seriousness and responsibility. Episodic evidence suggests his academic struggles stem more from lack of effort than intellectual incapacity, as he occasionally achieves good scores when motivated.

Relationships are central to Nobita. His profound, mutually dependent bond with Doraemon involves shared experiences in joy, danger, and sadness. Though frequently annoyed by Nobita's requests and laziness, Doraemon consistently provides support. Nobita deeply values this friendship, experiencing intense distress when faced with separation, as seen when Doraemon announces his return to the 22nd century. This triggers initial denial and anger, culminating in Nobita shouting hatred before fleeing. Subsequent reflection, guided by his father, leads to resolve: Nobita deliberately provokes Gian into a fight, enduring a severe beating to prove he can stand up for himself without gadgets, declaring "I won, by myself" to alleviate Doraemon's concerns. This signifies a pivotal moment of personal growth and emotional resilience.

His feelings for Shizuka Minamoto, his childhood friend and future wife, are significant. Nobita harbors a longstanding crush, often using gadgets to impress or assist her, though attempts frequently backfire or are overshadowed by Hidetoshi Dekisugi. Shizuka occasionally displays reciprocal affection, evidenced by correct answers to personal questions about Nobita and visible blushing. Their interactions include Nobita visiting her home to play or study, though she disapproves of homework copying. A recurring comedic element involves Nobita accidentally intruding on her baths via the "Anywhere Door," leading to physical retaliation. Despite occasional arguments causing temporary estrangements, they consistently reconcile. Their future marriage and son, Nobisuke, are established events.

Relationships with Takeshi "Gian" Goda and Suneo Honekawa are complex. Gian primarily functions as a bully, regularly beating Nobita for minor offenses and claiming it's essential for his own well-being. Despite this, moments of genuine camaraderie and loyalty emerge during greater threats; Gian occasionally assists Nobita when genuinely distressed. Suneo acts as an irritant, flaunting wealth and excluding Nobita, often under Gian's coercion. While frequently blaming Nobita for mishaps, Suneo also expresses pity and occasionally shares possessions after being rescued. Both relationships feature instances where Nobita collaborates with either Gian or Suneo against the other, indicating an underlying friendship. Nobita experiences intense jealousy toward Hidetoshi Dekisugi due to his academic excellence and friendship with Shizuka, though this rivalry diminishes in adulthood.

Future depictions show Nobita evolving into a more responsible adult. He marries Shizuka and fathers Nobisuke, who mirrors his own father's appearance with a slimmer build and different hairstyle, notably no longer requiring glasses. While retaining some laziness, he becomes smarter and more intelligent. His career path involves robotics engineering, a skill he uses significantly in one potential narrative to successfully revive a deactivated Doraemon. By age 55, his appearance reflects aging with slight slimming and visible wrinkles, his hairstyle reverting to a longer, childhood-like version. He maintains a kind-hearted, generous personality, offering guidance to his younger self about cherishing time with Doraemon. Future Nobita demonstrates awareness of his family's whereabouts, indicating involved parenthood.

Nobita's background involves being an only child whose initial future trajectory involved failure—marrying Gian's sister Jaiko, facing financial ruin, and perpetuating family poverty. This future prompts his descendant Sewashi to send Doraemon back to improve Nobita's circumstances. Doraemon's intervention alters this path, leading to Nobita marrying Shizuka and achieving a stable, improved life. The altered future includes a role reversal where Nobita's son bullies Gian's son. Despite episodic resets, key films and specials depict sustained growth, culminating in capable adulthood and recognition of Doraemon's positive impact.