Kirari relishing the experience of being “devoured.”

While Kirari Momobami presents herself as a refined and proper lady, she is, in reality, a calculating and manipulative individual with a psychopathic disposition, showing little regard for anyone but herself. A complete narcissist, she belittles others, firmly believing that everyone should play by her rules. This is evident when Mary Saotome declines her invitation to join the student council; Kirari dismisses her reasons as foolish and illogical.

As the architect of the notorious pet system, Kirari encourages mistreatment, bullying, and subhuman conditions for other students, revealing her sadistic tendencies. She has little concern for human life, focusing solely on her interests and believing that as long as the journey is entertaining, the outcome is inconsequential.

Kirari refers to the academy as her “aquarium,” taking pleasure in observing how individuals behave when they are at their lowest and must fight for dominance. She is indifferent to winning or losing, craving excitement, which allows her to mask her other emotions. An exceptional gambler, she frequently bets everything she possesses and takes considerable risks, with outcomes that consistently favor her. Her thrilling nature is reminiscent of Yumeko Jabami, as both derive pleasure from the suspense and the fading hope of their opponents, reveling in the suffering inflicted by their gambling outcomes. Ririka Momobami describes Kirari as selfish, believing her desires should be fulfilled, which is why she is willing to risk everything to make her dreams a reality.

Despite her generally cold and detached demeanor, Kirari demonstrates a genuine bond with her older twin sister, Ririka Momobami. Their interactions reveal that she truly treasures and loves her sister, expressing delight in Ririka’s growing self-confidence through her friendship with Mary Saotome. Kirari also displays affection toward her personal assistant, Sayaka Igarashi, and, despite their rivalry, she holds fond memories of playing games with her various cousins during their childhood.

Kirari amused by Yumeko’s challenge.

While Kirari typically maintains a calm and confident facade, there are moments when her composure is disrupted. This first occurs during a poker match against Rin Obami and Sumika Warakubami, where her excitement at facing her cousins quickly turns to shock and disappointment when both fold. Her composure is further shaken upon learning that Sayaka accessed the Hyakkaou Private Academy Vault—a fund of 3 billion yen collected by the student council—to buy votes from the academy’s student body to secure her victory. This revelation leaves Kirari visibly shocked, even causing her to collapse momentarily.

The situation escalates when Yumeko reveals that she distributed her votes by purposefully losing gambles to the housepets of the academy, allowing them to escape their status multiple times and dismantling the housepet system. This completely disrupts Kirari’s carefully crafted “aquarium,” which surprises her cousins, who notice the loss of her usual self-assured demeanor. Nevertheless, Kirari possesses the remarkable ability to regain her composure quickly after such shocks, seamlessly restoring her confident and collected disposition.