TV-Series
Description
Jean Rocque Lartigue is a fourteen-year-old French boy from the port city of Le Havre who serves as the male protagonist of the story. He is an orphan, having lost his mother at a young age, while his father, a wealthy ship captain and trader, has recently been lost at sea and is presumed dead. Following this loss, Jean has been raised by his aunt and uncle.

In terms of personality, Jean is defined by his optimism, generosity, and patience. He is a cheerful and well-behaved individual who remains friendly and devoted to his friends, even in the face of adversity. He consistently looks on the bright side of things, such as when his only pair of glasses is broken and he remarks that it is a lesson in detachment. However, he can also be socially awkward, particularly regarding romantic gestures and understanding the opposite sex, which often leads to misunderstandings with Nadia. He is also noted to have a somewhat passive temperament, generally tolerating Nadia's hot-headed outbursts with enduring calm.

Jean's primary motivation is his passion for science and invention. He is a self-taught genius inventor, capable of designing and building complex machines like airplanes and escalators at a very young age. Initially, his desire to build a successful flying machine is tied to a personal quest: he hopes to find his father, who disappeared after his ship was attacked by a sea monster. He refuses to believe his father is dead and is determined to use his inventions to search for him. As the story progresses, his motivations evolve. After learning the truth about his father's death, he channels his energies into building a gyrocopter to fulfill his promise to take Nadia to her birthplace in Africa.

Within the story, Jean is the catalyst for much of the early action. He first meets Nadia at the Paris Exposition in 1889, where he immediately becomes infatuated with her and rescues her from the jewel thief Grandis and her crew. This rescue launches their global adventure, which eventually leads them to the submarine Nautilus and the conflict with Neo-Atlantis. His role is that of the optimistic humanist inventor whose faith in technology is both tested and matured throughout the journey.

His key relationship is with Nadia. He is consistently loyal to her, vowing to take her to Africa, and his compassion and positive outlook gradually transform her personality, softening her pessimism and distrust. Their friendship becomes romantic, though Nadia struggles to express her feelings, often lashing out at Jean in frustration, which he continually forgives. He also develops significant relationships with the crew of the Nautilus, particularly Captain Nemo and Electra, from whom he learns about the dual nature of technology as a tool for good or evil.

Jean undergoes substantial development over the course of the narrative. His naive belief that technology is an unqualified good is shattered when he witnesses the destructive potential of the Nautilus as a "killing machine" and faces the loss of a friend in a contaminated engine room. He experiences a crisis of faith, even considering giving up inventing altogether, until Nadia encourages him to build a gyrocopter. Through this process, he learns valuable lessons about accepting help from others and accepting the past he cannot change. A pivotal moment occurs when he throws his father's favorite tool over a waterfall, finally accepting his father's death and choosing to move forward. By the end of the series, he has matured from a boy who relied on adults into a young man capable of taking responsibility, even surviving on a deserted island and providing for Nadia and a younger child.

Regarding notable abilities, Jean is an exceptionally gifted inventor and mechanic for his age. He built a working two-seat airplane long before the historical Wright brothers' flight, demonstrating remarkable theoretical knowledge and mechanical skill. He is also resourceful and a quick learner, absorbing advanced engineering concepts during his time on the Nautilus to improve his future inventions. Despite his genius, his early inventions suffer from reliability issues, often breaking down or failing at critical moments, a flaw he works to overcome. He wears round glasses that are a memento of his father.