Born in Konohagakure, a ninja village hidden in the leaves, Naruto Uzumaki was destined for greatness. When born, a powerful nine-tailed demon fox attacked his village. With a wave of its tail, the demon fox could raise tsunamis and shatter mountains. In a valiant attempt to save the village from destruction, the Fourth Hokage, the leader of the Hidden Leaf Village, sealed the demon fox within Naruto's newborn body. This was his final act, for the battle with the fox cost him his life. Despite the Fourth Hokage's dying wish that Naruto be viewed as a hero for serving as the container for the demon (a Jinchuuriki) the adult villagers of Konoha harbored a fierce hatred for him, with many believing that Naruto and the demon were one and the same. Cast aside as an inhuman monster, Naruto was outcast and ostracized by the villagers for reasons he could not understand. The children his age could only ever follow their parents' example; and they too came to harbor a fierce hatred for Naruto. Naruto eventually came to accept that he would live and die alone, and his external response was to perform harmless pranks on the village. Boisterous, raffish and full of life, Naruto soon came to display a somewhat unexpected determination to succeed and be accepted by others. Upon being assigned to "Team Seven" as a Genin-ranked ninja, his true potential soon became outwardly apparent. Vowing to become Hokage one day and using his will to never give in, Naruto saves the village from invading forces and earns his acceptance. Eventually, Naruto learns to harness the power of the Demon Fox sealed inside him to perform acts of strength far beyond what any other human is capable of. In all, Naruto is an admirable character whose sheer determination to succeed despite the odds, earns him respect and devotion from his fellow villagers.

The female protagonist. Makise Kurisu is a research member in Victor Qondria University's Brain Research Program. Her age group matches that of third-year high schoolers, but she skipped a grade through America's educational system. She is also famous in America for writing theses papers, part of which is covered in the news. Thanks to skipping a grade in America as a girl, she was envied by people around her, and ended up building a strong personality. She does not want to show weakness to others, so she always has a stern expression. However, she is very curious, and when she builds interest, she pokes into things. Occasionally, she has views that differ from regular opinions, such as, "The experiment data is more important than the subject's privacy." Rintarou often tells her, "Hey, you've got a pretty good sense of being a Mad Scientist," but she is not one to agree to such things personally. She is a tsundere. Rintarou has given her plenty of nicknames, in particular "Christina" (クリスティーナ) and "Assistant" (助手).