Kiyoko Shimizu managed the Karasuno High School boys' volleyball team in her third year. Standing at 166.2 cm tall, she had black hair, gray eyes, and a distinctive mole on her chin. She typically wore pink-framed glasses and black leggings year-round to conceal scars from her middle school track and field career, where she specialized in hurdling and sustained frequent leg injuries. This athletic background sharpened her reflexes, enabling her to protect first-year manager Hitoka Yachi from a stray volleyball. Recruited as manager by Daichi Sawamura in her first year without prior volleyball knowledge, Kiyoko independently mastered the sport's rules, referee signals, and managerial duties. Though initially perceived as aloof and reserved, her dedication manifested through actions like repairing and washing Karasuno's team banner to boost morale. Public speaking proved challenging, notably making Hinata overly nervous during pre-match encouragement attempts. Her character development intensified during her third year when seeking a successor, leading her to recruit Yachi. Mentoring Yachi prompted Kiyoko to become more expressive, smiling frequently and using humor to ease Yachi's anxiety. This relationship fostered openness, with Kiyoko sharing personal experiences about her track career and the origin of her leg scars. Kiyoko provided consistent operational match support, recording statistics, handling equipment, and assisting injured players. During critical moments, like the Spring High Preliminary against Shiratorizawa, she comforted Sugawara by holding his hands and assured the injured Tsukishima of the team's resilience. She also intervened to shield Yachi from unwanted advances by opponents like Johzenji High's Terushima. She encouraged initiative through curiosity over obligation, advising Yachi: "I don't think everyone has to like something before giving it a try... To get started, I just think you need a little bit of curiosity." At the Tokyo Nationals, she emphasized effort's value regardless of outcome, reflecting: "I may not stand on the court... But, right now, at this very moment... I stand with them on the front line." During a New Year's shrine visit with Daichi, Sugawara, and Asahi, she redirected their focus from seeking luck to self-reliance, stating: "You aren't going to win any games just because you prayed to the gods for it... you've got nothing to worry about." Post-graduation, she married teammate Ryūnosuke Tanaka by November 2018, changing her surname to Tanaka. In later years, she attended professional volleyball matches, interacted amicably with former Karasuno players, and adopted a shorter hairstyle without glasses or leggings.