Mitsuru is the only child of the current head of the Kirijo Group, Takeharu Kirijo. She is also the school’s top ranking valedictorian and student council president. In battle she wields one-handed swords such as rapiers and sabers. Her Personas excel at ice spells, and she is the most powerful offensive magic caster aside from the Main Character.
Mitsuru has been battling Shadows for a long time. Upon discovering of the Main Character’s potential as a Persona-user, she, along with Ikutsuki, invites him into SEES. At the beginning of the game she stays behind as a Support character, offering analysis and advice. She joins the party in battle only after the discovery of Fuuka Yamagishi, whose analysis power is much stronger than Mitsuru's.
Mitsuru is one of the girls that Main Character can date over the course of the game. In order to attract such an ambitious young woman he must maximize his intellect statistic, and rank first in his class for at least one exam. If the player makes the correct choices, Mitsuru will fall in love with the Main Character, and the Main Character will help free her from some of the expectations attached to her family name.
While Mitsuru herself has not made any sort of appearance in the anime sequel, Persona -trinity soul-, a young girl bearing an uncanny resemblance to her is shown in the first episode bringing one of her fingers up much like the Main Character did near the end of the game.