Makina Irisu is a first-year student at Mihama Academy and a main heroine in the series. She comes from the powerful and influential Irisu family, a matrilineal financial conglomerate with deep connections in Japan. Makina was once considered a prodigy and was the designated successor to the family. However, her life took a tragic turn eight years before the main story begins. Her father, Masataka Irisu, uncovered corruption within the family and was killed in a staged kidnapping, shot in front of her. Makina was left tied up next to his body for six days before being rescued. The psychological trauma left her in a near-catatonic state for years. It took three years before she could respond to basic questions, two more to form coherent thoughts, and another year to express normal emotions. The branch family used the incident to sideline her, faking her continued hospitalization and secretly enrolling her at Mihama Academy to prevent her from becoming heir. Her younger half-sister, Sarina, took her place. Despite this, Makina retains personal assets of about seventy million yen.

Makina has a petite, childlike appearance with light brown hair styled in twin pigtails tied with blue ribbons and large purple eyes. She is often seen wearing mismatched knee-high socks. Her personality is initially extremely shy and withdrawn around strangers, driven by a deep fear of rejection. Once she becomes comfortable with someone, she reveals an energetic, playful, and childish side. She has a verbal tic, frequently ending sentences with noyosa. Her speech and behavior can be unpredictable and eccentric, leading many to describe her as difficult to understand or even awful after a brief conversation. After forming a bond with Yuuji Kazami, whom she affectionately calls Onii-chan, she becomes more outgoing and confident. She begins to emulate his disciplined demeanor, sometimes acting like a miniature drill sergeant. She also trains in basic self-defense and marksmanship under Yuuji’s guidance, developing notable proficiency with a pink rifle.

Makina’s primary motivation is a longing for safety and a stable family. Her traumatic past has left her craving affection and protection. She adores Yuuji as a brother figure and eventually bribes him to become her papa, forming a unique pseudo father-daughter relationship that provides her with a sense of security. She also looks up to Amane Suou as an older sister, often staying in Amane’s room for comfort and relying on her for meals and emotional support. Among her classmates, she enjoys teasing Michiru Matsushima and Yumiko Sakaki, and gradually develops friendly rapports with everyone at Mihama Academy. Her relationship with her biological mother is strained, as she harbors resentment for the mother’s role in her father’s death and her subsequent exile.

In the story, Makina’s role is that of a heroine whose arc centers on confronting her past trauma and the family’s betrayal. She demonstrates remarkable bravery and selflessness when it comes to protecting Yuuji, showing the most resolve among the girls in critical situations. Through her bond with Yuuji and her friendships at the academy, she gains confidence and learns to trust others, evolving from a withdrawn, traumatized girl into a more assertive and protective individual. Her latent talent and prodigious intelligence resurface as she adapts to her new environment. Overall, Makina’s journey is one of healing and finding a new sense of belonging beyond her fractured family lineage.