Misaki Shidō, the 15-year-old captain of the Kurotama Middle School Soft Tennis Club, holds the national championship title in the individual competition. She possesses dark blue hair and striking pink eyes. Hailing from a wealthy family that owns an entire mountain, Misaki trains at Shidou Hall, their private facility perched on the summit. This exclusive ground features an extensive, rigorously designed obstacle course built to extreme specifications, which she uses to maintain her elite athletic condition. Her signature technique, the "Invisible Counter," propels the ball beyond light speed, rendering it temporarily invisible to opponents and generating enough force to physically sweep them off the court.

Despite her formidable on-court reputation and intense competitive demeanor, Misaki harbors a contrasting private side. She struggles with deep self-consciousness about her physical development, particularly her lack of chest size compared to peers. Off the court, she exhibits shyness and acute embarrassment regarding her strong affinity for cute, cuddly items. Misaki secretly collects merchandise featuring "Nyantaro," a character depicting small cats found on fabrics like underwear or bedsheets, and maintains a significant hoard of stuffed animals. She fiercely guards this softer side, fearing its exposure would shatter her imposing champion image.

Her attempts to conceal this personality facet are constantly undermined by Yura Hiratsuka, a subordinate club member who covertly photographs Misaki in compromising situations, especially those highlighting her plush toy or cat-themed interests. As captain, Misaki employs strict surveillance tactics against rivals like Shiratama Middle School's Soft Tennis Club, directing Yura to gather detailed intelligence on opponents' strengths and weaknesses. Her leadership emphasizes meticulous preparation and psychological dominance, underpinning Kurotama Middle School's consistent regional championship victories. Her narrative role centers on being a skilled antagonist whose hidden vulnerabilities and hobbies create comedic or situational contrasts to her serious athletic persona.