Goddess of Victory
Aigis

3
Aigis is an Anti-Shadow Suppression Weapon (seemingly the last one in existence) and a member of S.E.E.S. who also attends Gekkoukan High School. She is a machine that gradually awakens to human emotions.
Aigis appears as an android with short, blond hair and light blue eyes. Ikutsuki explains that her humanoid shape allows her to process thoughts like a human making it easier to handle a Persona. When she transfers and appears in Gekkoukan High, she wears the generic winter female school uniform, which also includes black knee-length socks and brown loafers, but retains her red ribbon (given by Yuu Kimijima in Aegis: The First Mission) except at the beach excursion in Yakushima, a brief school field trip in Kyoto (in which she wears a haori) and the post-New Year's Day when she wears a kimono at the nearby shrine.
Aigis' initial personality is simply a robot designed to obey orders, although she is drawn to the protagonist and states that it is very important for her to be by his side, going so far as to hug them in front of everyone. Her desire to protect the protagonist is so strong, in fact, that she was able to overcome Ikutsuki's programming and free the entire team from their shackles, when Ikutsuki had attempted to sacrifice them to bring forth the Fall. As a result of having no emotions, Aigis' social skills are more-or-less non-existent; it's frequently noted on-screen that while she may look human, she is far from passing as such.
She is prone to doing very strange and socially unacceptable things, such as breaking into the protagonist's room to wake him up and requesting to be on standby in their room, which Yukari calls her out for. A video recording shows that she has a habit of breaking into his dorm room at night in order to check on him, even going so far as to keep a record of how long it takes her to pick the lock, In Falling Down, she even goes so far as to sneak into the boys' rooms during the group's stay in Kyoto.