Takeshi Gouda, universally known by his nickname Gian, is a main character in the Doraemon series. The nickname "Gian" is derived from the English word "giant," a fitting description for his large and imposing stature compared to his peers. He has black hair, tan skin, and a build that suggests both strength and heaviness. His typical outfit in the 2005 anime includes a light orange shirt with a red stripe, brown pants, and gray shoes.

Gian's personality is defined by a stark and often humorous contrast between his aggressive actions and his hidden softer side. He is the neighborhood bully, known for his quick temper, his selfishness, and his habit of taking other children's toys and belongings under the pretense of "borrowing" them. He rules his peer group through physical force, with Nobita being his most frequent target. However, Gian possesses a profound lack of self-awareness, most famously regarding his singing voice. He considers himself a gifted vocalist and singer, but in reality, his voice is incredibly loud and off-key, often causing listeners to pass out or flee in terror. Despite this, he regularly forces his friends and neighbors to attend his terrible concerts and demand they praise his performances. He is similarly confident in his homemade cooking and fashion sense, both of which are equally dreadful.

Gian's primary motivation is a desire for attention, admiration, and control, which he seeks through physical dominance and his misguided artistic pursuits. He craves being seen as a leader and a star, and he becomes enraged when his authority or talents are questioned. Underneath this tough exterior, however, is a genuine, if inconsistently displayed, sense of loyalty, justice, and compassion. He does not hesitate to help Nobita and the others when they face real danger, especially in the feature-length movies, where he often acts as the muscle of the group. This duality is a core part of his role in the story. In everyday episodes, he functions as an antagonist whose bullying creates the conflicts that drive Nobita to seek help from Doraemon. In longer adventures, he transforms into a reliable and courageous ally, showcasing that his heart is ultimately in the right place.

His relationships are central to the series. He has a codependent yet combative friendship with Suneo Honekawa, who often acts as his sycophantic sidekick. While they appear to be good friends, Suneo secretly fears and resents Gian, and Gian does not hesitate to bully him as well. His relationship with Nobita is the most complex. On one hand, he ruthlessly torments Nobita, with one translation stating, "If I don't bully Nobita a day, I can't eat and sleep any more". On the other hand, he is frequently the first to support Nobita's decisions in a crisis, and moments in episodes and movies show him genuinely concerned for Nobita's safety, such as rescuing him from falling or offering him medicine when sick. This suggests a deep, albeit unspoken, bond of friendship. Gian is also genuinely terrified of his mother, a stern woman who runs the local grocery store and does not hesitate to physically punish him for shirking his responsibilities or bullying others. In contrast, he is fiercely protective of his younger sister, Jaiko, and often uses his strength or tries to use Doraemon's gadgets to help her pursue her hobby of drawing manga, sometimes to her embarrassment.

Gian undergoes subtle but significant development. While he rarely changes his bullying ways permanently, there are moments of introspection where he realizes his behavior drives others away. In one notable story, after a failed attempt to become gentle, he loses his temper and regresses, showing that change is difficult for him. Despite this, his growth is shown not through a loss of his aggressive personality, but through an increasing reliability as a friend. He learns that winning is not everything; for example, he continues to force the clumsy Nobita to play on his self-named baseball team, the Giants, not just to have a scapegoat for losses, but because they are his friends and team members. Gian's notable abilities include his immense physical strength, making him the strongest among his friends, and his athletic talent, particularly in baseball where he is the team captain. His lack of fear in the face of monsters or danger is also a consistent and useful asset during adventures.