Takeshi Goda, universally known by his nickname Gian, is a central character in the Doraemon series. The name Gian is derived from the English word "giant," a direct reference to his most obvious characteristic: his large, imposing physical stature, which is often attributed to a combination of natural build and a fondness for food. He was born on June 15 and is typically ten years old, appearing with tan skin and black hair, almost always dressed in his signature color, orange.

Gian's personality is a study in contradictions, making him one of the most complex figures in the neighborhood. On the surface, he is the undisputed bully, ruling through brute force and a volatile temper. He operates on a selfish philosophy, famously declaring, "What's mine is mine. What's yours is also mine," and he frequently takes toys, manga, and other belongings from other children under the pretense of "borrowing" them. His favorite target is the hapless Nobita, who often becomes the recipient of both physical intimidation and verbal insults. To the point that Gian himself has stated that if he does not bully Nobita for a day, he cannot eat or sleep. Despite this antagonistic role, Gian is not a villain in the true sense. Deep within, he possesses a simple big heart and a strong, if sometimes misguided, sense of loyalty. When his friends are in genuine danger, particularly during the long-form movie adventures, Gian does not hesitate to risk his own safety to help them, often being the first to support Nobita's decisions in a crisis.

Several key motivations and fears drive his behavior. He has an unshakeable, yet completely unfounded, confidence in his own abilities, specifically his singing voice and his cooking. He forces the entire neighborhood to attend his horrendous singing concerts and to eat his terrible home-cooked meals, believing himself to be a great artist. He is also deeply passionate about baseball, serving as the captain and the star player of the local Giants team. He prioritizes winning above all else and frequently and abusively blames his less-skilled teammates, namely Nobita and Suneo, for any losses.

Despite his domineering personality, there is one person who terrifies him: his mother, who runs the local grocery store. Her anger is the only thing that can immediately subdue him and force him to behave, a weakness that Nobita and Doraemon occasionally exploit. Another core motivator is his deep love for his younger sister, Jaiko. He is extremely protective of her and supports her dream of becoming a professional manga artist, even going so far as to force his friends to read her work or using Doraemon's gadgets to help her, often much to her annoyance.

Gian's role in the story is primarily that of an antagonist and a source of conflict in the daily lives of Nobita and his friends. Many episodes revolve around their elaborate schemes to avoid his concerts, his birthday party, or his violent outbursts. However, his role evolves beyond that of a simple bully. He is an integral part of the core friend group. His relationship with Suneo is particularly notable; Suneo acts as his sycophantic sidekick, offering his possessions and companionship to avoid Gian's wrath, though the two are genuinely close friends who spend a great deal of time together. His relationship with Nobita is the most complex. While he bullies him relentlessly on a daily basis, underlying moments of genuine friendship surface, such as when Gian holds Nobita's hand to save him from drowning in a movie or gives him medicine when he is sick. He shares a more respectful friendship with Shizuka, as he rarely bullies her and will sometimes listen to her pleas to stop his antics.

While Gian rarely undergoes permanent change, the character does display moments of self-reflection and development. After a particularly harsh lecture from Doraemon about his behavior, he once realized how unpopular he was and begged for a chance to be a better person. Although this attempt at reform typically fails due to his own temper or the taunts of his peers, it reveals a desire for genuine friendship beneath his gruff exterior. In glimpses of the future, it is shown that he eventually overcomes his worst flaws and becomes a good father.

In terms of abilities, Gian's notable talents are almost entirely physical. He is the strongest and most athletically gifted child in his peer group. He also possesses a tremendous, though unpleasant, lung capacity for his terrible singing, which is portrayed as so appalling that it can cause listeners physical pain or make them pass out. His inability to recognize the terrible quality of his own voice is perhaps his most defining and enduring trait.