Shiho Sawaragi holds the position of vice-president in her high school class, functioning as its de facto organizer. Her police officer father's profession deeply shapes her personality, forging a strong sense of justice and aversion to dishonesty. Athletic and a dependable combatant within her group, her appearance features waist-length black hair with straight bangs and dark blue eyes. She typically wears a high school uniform comprising a brown blouse with a red sailor-style collar, a black pleated skirt, knee-length black socks, and black shoes, later adopting the uniform of the Observers.
Her character demonstrates moral integrity and dedication to protecting friends and others, though she occasionally displays shyness in inappropriate situations. She harbors romantic feelings for Yuuichi Katagiri, a central figure in her social circle. This commitment to justice occasionally leads her to conceal suspicions, such as initially refusing to investigate the theft of her class's trip funds due to her belief that Yuuichi might be involved.
Shiho's entry into the Tomodachi Game occurs when she inadvertently loses the class's trip funds, making her a target of suspicion and bullying. This forces her participation to resolve the resulting debt. Following the second game round, she and Makoto Shibe endure intensified bullying, culminating in her disappearance. She reappears as a hostage of the game's administrators, used to deter her father's investigation into the game and his attempts to expose traitors within her group. After this ordeal, she rejoins the games—first replacing Kei in Game #2.2, then fully participating in the final Game #3 to uncover the truth behind the Tomodachi Game and Yuuichi's past.
Her backstory includes a traumatic childhood abduction that fractured her family and friendships. This event left a permanent scar from her right shoulder to her chest, typically concealed by clothing. It drove her to train rigorously in martial arts, achieving a black belt in karate and developing strength to knock down trees and incapacitate multiple men. She vowed never to be victimized again, cementing her role as a protector. A childhood friendship with Tenji Mikasa adds complexity to her relationships, though initially hidden from the group.
Throughout the games, Shiho repeatedly showcases combat abilities. She exhibits superhuman physical traits including peak human movement speed and subsonic reaction times, such as narrowly dodging paintball bullets. Her durability allows her to withstand attacks from physically superior opponents like Subaru Gaku. She also demonstrates notable stamina and lifting strength, exemplified by carrying Yuuichi over long distances. Her tactical intelligence is above average, with particular aptitude for combat strategy and analysis.
Her development involves confronting the erosion of her ideals as Yuuichi's manipulative and morally ambiguous nature surfaces. Despite mounting evidence against him, she persistently seeks to verify his true character, balancing her symbolic role as a beacon of justice with personal loyalty. This conflict peaks when Yuuichi seemingly loses a game and tasks her with clearing it, leading her to threaten others—a departure from her typical behavior requiring Shibe's intervention to resolve. Her journey remains defined by this tension between unwavering trust and the pursuit of truth.