Midori Kageishi is a second-year high school student and the younger sister of Sumire Kageishi, a teacher at the same school. She serves as the president of the drama club, a position she holds despite a notable lack of natural talent in acting, scriptwriting, and directing. The club is at risk of being disbanded, and her leadership is driven by a strong sense of responsibility rather than innate skill.

Academically, Midori is an exceptional honor student who consistently achieves perfect scores, reflecting a disciplined and serious approach to her studies. Her personality is marked by extreme diligence and a firm belief that effort alone can lead to perfection in any field. This conviction serves her well in academics but proves insufficient in the artistic realm of drama, where her capabilities fall short.

Her primary motivation is to keep the drama club active, even though her own abilities as a performer and director are questionable. In the story, she functions as a supporting character whose struggles highlight the gap between hard work and innate talent. Her key relationship is with her older sister Sumire, though she also interacts with the main cast of students at the school. Over the course of the narrative, Midori faces the challenge of reconciling her high standards with the reality of her limitations, though specific development arcs are not extensively detailed in available information. Her notable abilities include outstanding academic performance and a relentless work ethic.