Mitsuru Kirijo, sole heir to the powerful Kirijo Group conglomerate, serves as Gekkoukan High School's student council president. She founded the Specialized Extracurricular Execution Squad (SEES) to combat supernatural Shadows. Her family history is deeply entwined with the Dark Hour, a hidden time between days when Shadows emerge. Her grandfather, Kouetsu Kirijo, initiated experiments that accidentally created the Dark Hour and Shadows while developing a time-manipulation device, involving Yukari Takeba's father, Eiichiro Takeba. During the July full moon events in *Midsummer Knight's Dream*, Mitsuru leads SEES against Shadows including the Arcana Hierophant and Lovers. On a summer trip to Yakushima, her father, Takeharu Kirijo, reveals the full truth of the Kirijo Group's role in creating the Dark Hour and Shadows, causing significant distress to Yukari. Mitsuru supports her teammates through this revelation. She later oversees the induction of new SEES members: Ken Amada, an elementary school student who awakens his Persona after witnessing Shadows resembling his mother's killer, and Koromaru, a dog who also awakens a Persona. Mitsuru provides tactical leadership against the antagonistic group Strega, coordinating SEES during confrontations like battles against combined Shadow Arcanas Chariot and Justice, relying on allies like Shinjiro Aragaki. When Shinjiro's past involvement in Ken's mother's accidental death surfaces, Mitsuru and Akihiko Sanada disclose this to SEES. Shinjiro's subsequent sacrifice to protect Ken from Strega leader Takaya Sakaki profoundly impacts the group. Her personality blends aristocratic poise with social inexperience. Raised in privilege, she lacks exposure to commonplace activities and foods like hamburgers or ramen. Formality defines her initial interactions; she addresses most SEES members by last names, reserving first names for close associates like Akihiko Sanada, known since junior high. Despite a composed exterior, she exhibits occasional social awkwardness and discomfort in casual settings, reacting with shyness to compliments or unfamiliar scenarios. Her leadership emphasizes academic excellence and discipline, enrolling SEES members in summer classes without prior consultation. In combat, Mitsuru wields a rapier and commands ice-elemental magic through her Persona, Penthesilea. After Fuuka Yamagishi joins SEES, Mitsuru transitions from support to frontline fighter, leveraging Fuuka's Persona for tactical analysis. She is weak against fire-based attacks. Her character evolves across other *Persona 3* media. She loses her father to Shuji Ikutsuki's betrayal, initially shattering her resolve. Supported by Yukari, she regains her purpose and eventually leads the Kirijo Group after high school. In spin-offs like *Persona 4 Arena*, set two years later, Mitsuru establishes the Shadow Operatives task force to investigate Shadow incidents, appearing as a university student wielding her evolved Persona, Artemisia. Additional appearances include rhythm games (*Persona 3: Dancing in Moonlight*) and crossover titles (*BlazBlue: Cross Tag Battle*), maintaining her combat abilities and aristocratic demeanor.