Kiyoko Shimizu is a third-year student at Karasuno High School and the manager for the boys' volleyball team. Standing at 166.2 cm tall with a birthday on January 6, she presents a reserved and serious demeanor, diligently carrying out her managerial duties. With no prior volleyball knowledge, she taught herself the sport's rules and regulations after joining. Her background includes middle school track and field, specializing in hurdling, which left her with leg injuries and scars. Consequently, she consistently wears leggings, even during summer. This athletic history contributes to her physical capabilities, such as swiftly deflecting stray volleyballs to protect others. Her appearance features shoulder-length black hair, often styled with one portion tucked behind her left ear, grey eyes, a beauty mark on her chin, and thin-framed pink-rimmed glasses. As manager, she typically wears the team's lavender tracksuit or the official manager uniform. Post-timeskip, her hair is shorter with bangs swept to the side, and she no longer wears glasses or leggings. Kiyoko demonstrates quiet dedication to the team, exemplified by repairing and washing Karasuno's old banner to boost morale. Though initially perceived as aloof, she shows care through practical support, assisting players during matches and managing logistical tasks like uniform distribution and tournament paperwork. Her reserved nature shifts after recruiting first-year Hitoka Yachi as her successor manager. She becomes more expressive, smiling frequently and using humor to ease Yachi's anxiety. This mentorship deepens into a close friendship where Kiyoko shares personal details, such as the origin of her leg scars, noting Yachi is "the first person I've been able to talk to like this." Key moments include her direct intervention to protect Yachi from harassment by players like Terushima, reassuring Tsukishima during a critical match against Shiratorizawa that the team "won’t have lost" by the time he returns from injury treatment, and offering comfort to Sugawara by holding his hands to alleviate nervousness. She also inspires confidence in the third-years during a shrine visit before nationals, redirecting their focus from seeking luck to trusting their abilities. Post-timeskip, she marries Ryūnosuke Tanaka, changing her name to Kiyoko Tanaka. She attends professional volleyball matches, interacts warmly with former Karasuno players, and displays increased openness in social settings. Notably, she stops covering her leg scars, embracing them as "badges of honor"—a phrase originally coined by Yachi.