Jeremie, a 12 year old boy, is one of the main members of the gang, because he is the one who operates the super computer . Without his knowledge, no one would be able to be transfered on Lyoko or to contact Aelita, because Jeremie is the only one who masters the parts of the system or the general technical of programming, virtualization, materialization, or tactics against X.A.N.A.He is in the same class than Odd and Ulrich, he is a very bright student, a smart and gifted boy. He succeeds in every class, except gym, and is considered a truly gifted child by a lot of teachers and by the school psychologist, who decided he needed to go in a special school for gifted children (in Plagued). For Jeremie, it would mean to leave his friends, to give up Lyoko and all hope to materialize Aelita. For him, it’s of course out of question. He is often considered, and sometimes for good reasons, as the teachers’ pet, and therefore he has not only friends. Cruel, jealously looked upon by Herve, the "challenger" of Sissi's band, and perceived as a boring and stupid unintellagent person by the other schoolkids, he frequents few peoples except his group of friends, the "leader" of which he is unmistakably. Indeed, Jeremie is the leader and the others obey him confidently except Williem, because nobody other than him is capable enough of judging a delicate situation. Wearing simple trendy clothes, and big glasses, his clothes reflect his modest and discreet character. Nevertheless, Jeremie is nothing of a stereotype, because except his aspects and except his school results, he has a really well asserted personality. With much kindness and a endless generosity, he often tends to make cross the interests of the others before his. Actually, his character is rather close to Yumi’s one, with less maturity because he let himself bring in unreasonable considerations, sometimes to forget the reality. Fortunately, the characters of the friends being additional, everything is supposed to be for best between them. Also internal, Jeremie doesn’t see very often his parents, whose information is not given during the first season. Finally, his friends had fast judged him in his true value and appreciate the real qualities of this genius slightly handled by the reputation and the gossip of schoolkids.
Slightly contained on himself, Jeremie spends the most of his time in front of his computer screen, under the friendly glance of Einstein, the portrait appearing over his bed. Non-stop Programming, going without sleep at night, he tempts by all the ways to end in the realization of his ultimate dream: to materialize Aelita in the real world and be able to deconnect X.A.N.A. once for all. Constantly in "cyber - conversation " with this one, the relations with Aelita are quite particular. It is easy to suspect that there is certainly not only a simple friendship between those two beings, at the same time so different, but at the same time particularly close affectionately. So, he spends hours in private chatting with his friend, explaining to her and making her discover the real world in endless conversations, to prepare her for her future "journey" on Earth. A real complicity connects these two persons, but also a chance for X.A.N.A. who comes out quiet as long as Aelita is virtual. The attacks of X.A.N.A. have no other effect than strengthened his courage and his determination, encouraging him tobreak any obstacles without ever discouraging. Without this privileged relation, we guess his mood would have held out, after a lot of failures and successive disappointments.
Contrary to his friends, Jeremie doesn’t go on Lyoko, staying behind the screen of the supercomputer to help them in their missions. He warns them of threats and of traps of Xana, while making what is in his possibility to slow down and counter it in its evil plans. Furthermore, he follows permanently the evolution of the situation in the real world, because he knows well that he has little time and that it is necessary to act before it is too late. Still searching new possibilities to fight X.A.N.A. and reach his purposes, Jeremie is never out of inspiration, tempting by all the means to drill the numerous mysteries of Lyoko and tinkering ceaselessly the connections of the multiple devices of his computer paradise.
We can wonder which real role Jeremie played in the discovery of the secret laboratory, and in which circumstances he met Aelita. Is it he who woke up X.A.N.A.? Is it he who programmed the virtual forms of the heroes? At least, he can act directly on Lyoko and on the progress of the fights, and well plans to take advantage of it.
In the first season, he broke his fears and makes exception for the rule virtualising him twice, in the episodes "Frontier" and "Ghost Channel," not keeping a particularly pleasant recollection of these adventures…
As a conclusion, we can say that Jeremie is absolutly not a secondary character because he doesn’t fight directly on Lyoko. With his enormous intellectual capacities, he is a main character as the other ones of the gang.