Mari is introduced for the first time in the plug of Evangelion Unit-05 just as she is about to sortie to take down the rogue Third Angel, which is attempting to escape from Bethany Base. She caused a furor among fans after months of teasing and her ultimate reveal. Before her actual name surfaced, Mari was known exclusively among fans as "Glasses Girl" (among Japanese fans, めがねのこ, megane no ko, meaning the same thing). Mari's entire name was at last revealed in a revised version of the poster included with the first issue of Eva Extra.
Later, one of the official movie posters included a "teaser" for her full name: showing the "Mari" part, and substituting the remaining characters with asterisks ("*** Mari *******"). Her first name was originally unveiled in the Nintendo DS Petit Eva: Evangelion Game game. By finally making a reference to Raideen, Anno felt, Izubuchi could "save Buc-chan's face." Izubuchi speculated that another character from Raideen served as inspiration for Rei and Asuka. The choice of Mari was also done as a nod to another friend of Anno, Yutaka Izubuchi, creator of RahXephon. Mid-way through productionh Anno also considered changing Mari's name yet again to Chizuru, as a homage to Chizura Nambara from Combattler V, and as a gesture to please "Shō-chan", refering to his friend and colleague Shōji Kawamori, creator of the Macross mecha franchise. Originally, Anno considered naming her Mariko, borrowing from one of his wife Moyoco Anno's manga, but instead opted for using the name of Mari Sakurano, from Brave Raideen. Strictly speaking, neither "Illustrious" or "Makinami" (written as 真希波, "noble true wave") are real surnames, although this may be nothing more than a creative liberty. The two names may be intended to, as in Asuka's case, represent a mixed heritage: here, British and Japanese (at minimum). Mari is named after two World War II warships, the Japanese destroyer Makinami (巻波, "overflowing waves") and the British aircraft carrier HMS Illustrious. This makes it unlikely that she was the one who sabotaged it, although her being an acquaintance of Ryoji Kaji is suspicious. She also appears to be aware of the Evas' sentient nature to some extent, going so far as to directly addressing them in a compassionate tone and even whispering goodbye to Eva-05 after its destruction. Her first engagement with the Third Angel used no tactics whatsoever but saw her attacking the Angel head-on, chasing it outside of the base and pinning it down before self-destructing. In combat, she is extremely aggressive and despite her inexperience, she is shown to be an expert pilot on the level of Asuka, if not higher. A pilot designation has not been provided, assuming Mari officially has one (in-universe). It is implied that Mari works for an unknown third party. She also appears to have reduced inhibitions and even identifies Shinji as a pilot in their first encounter by crawling up to him on all fours and sniffing for the smell of LCL. Her repeated comments suggest that she has a liking to the smell of LCL. Out of all the pilots, she is the only one who admits that she genuinely enjoys piloting. Mari is shown to have an enigmatic personality. 5 Evangelion 3.0 + 1.0: Thrice Upon a Time.2 Evangelion 2.0: You Can (Not) Advance.Later, she is obscured by Meursault's introspection, and she drifts away, from the plot, from Meursault, to everyday life and everyday routine. When Meursault is arrested and sentenced to death, her dreams also die. She has her daydreams and is happier than we have ever seen her. She is much more of a romantic than he is. But one should remember that she had great hope for her new life in Paris with Meursault. Marie is on the fringe of this novel, even though Meursault has agreed to marry her. Like Meursault, she does not demand much from life or from other people. Meursault will probably be an adequate husband he will probably have a steady job, an income that she needn't worry about, and she doesn't ask much more from a man.
She is attracted to Meursault because he enjoys many things that she does and also because he is a little "different." When Meursault agrees to marry her, Marie is happy. Like Meursault, she has had rather unimportant jobs: he is a clerk, she was a typist.
She is frightened and terrified when Meursault is arrested her life, one would guess, has never been confronted with such drama. She wants marriage, children, enjoys casual sex, swimming, movies, and outings to the beach. The few clues that we have about Marie's personality come from Meursault, but he is not given to analyzing himself or other people and so we know little other than that she seems, basically, an uncomplicated middle-class young woman.