Takeshi Gouda, almost universally known by his nickname Gian, is a central figure in his neighborhood and a constant presence in the lives of his peers. The name Gian is derived from the English word giant, a fitting description for his large, imposing stature, which is characterized by a robust build, black hair, and tan skin. He is most often seen wearing his signature orange shirt, though the specific design of his outfit has varied across different adaptations of the story. As a child, he lives with his parents and his younger sister. His mother, who runs the local grocery store, is notably the only person Gian truly fears, and her harsh discipline is a primary check on his behavior. In stark contrast to his aggressive public persona, Gian is deeply protective and caring toward his younger sister, Jaiko, and he frequently goes to great lengths to support her ambitions, particularly her dream of becoming a professional manga artist.

Gian's personality is a complex mix of aggressive bullying and surprising loyalty. He is best known in the neighborhood as a bully who uses his superior strength to intimidate others, frequently taking their toys, comic books, or other possessions under the pretense of borrowing them, often with the justifying motto that what belongs to others rightfully belongs to him. His quick temper and violent outbursts are a regular source of trouble, especially for his frequent target, Nobita Nobi. However, Gian is not without his own peculiar delusions of grandeur. He is utterly convinced of his own talent as a singer, despite his voice being notoriously awful to the point of causing physical pain and even making listeners pass out. He regularly forces the entire neighborhood to attend his terrible concerts, which he may combine with his equally disastrous homemade cooking. His favorite food is stuffed capsicum. Despite these overbearing traits, Gian possesses a strong moral code when it truly counts; he never hesitates to come to the aid of his friends when they face a genuine, serious crisis, a trait that becomes especially prominent in the feature-length films.

The motivations behind Gian's actions are often dual-layered. On the surface, he is driven by a desire for power and recognition, wanting to be seen as the strongest, best singer, and most talented person in his circle. His bullying and theft are expressions of his dominant role in the neighborhood pecking order. Beneath this tough exterior, however, he craves genuine friendship and respect, even if he does not know how to earn it properly. He has moments of clear self-reflection, such as when no one wants to attend his birthday party, leading him to question why he is disliked and to express a sincere, though often short-lived, desire to become a better person. His role in the story is thus multifaceted: he serves as an antagonist who creates conflict for Nobita and Doraemon to solve, but he is also a vital member of the core friend group whose strength and courage are indispensable during their larger adventures.

Gian's key relationships define much of his character. His dynamic with Nobita is the most central, characterized by frequent physical and emotional bullying that forces Nobita to seek Doraemon's help. Yet, paradoxically, Gian is often the first to support Nobita's decisions during adventures and has shown on multiple occasions that he deeply cares for him, even saving his life. He maintains a more transactional friendship with Suneo Honekawa, who acts as a wealthy and fawning sidekick, though Gian will not hesitate to bully Suneo as well. With Shizuka Minamoto, Gian is noticeably less aggressive, largely refraining from bullying her and sometimes listening when she scolds him for his behavior. As the captain and strongest player of the local youth baseball team, the Giants, he ruthlessly blames teammates like Nobita for losses, yet he is also the one who organizes the team and insists they play.

Gian shows subtle but notable development over the course of the series. While he almost always reverts to his bullying ways in everyday situations, his experiences, particularly during the annual feature films, consistently reveal his capacity for growth. In these life-or-death scenarios, his bravery, loyalty, and protective instincts take precedence over his selfishness, proving him to be a reliable and heroic figure. These adventures allow him to channel his strength and assertiveness for the good of the group, showcasing that his character is not simply a one-dimensional bully but a friend with significant, if inconsistent, redeeming qualities.

Gian's notable abilities are almost entirely physical. He is, by a wide margin, the strongest and most athletically gifted child in his group, possessing immense raw power, high durability, and great stamina. This physical prowess makes him a formidable fighter and the star player of his baseball team. His other defining ability is his terrible singing voice, which is so powerful that it can be used as a form of assault, shattering glass or incapacitating anyone who hears it, a fact that is completely lost on Gian himself. Despite his lack of self-awareness, his brutal honesty and unwavering self-confidence in his own talents are, in their own way, a unique part of his character.