Saiai Kinuhata is a Level 4 esper affiliated with the dark side organization Item in Academy City. She wields the ability Offense Armor, manipulating atmospheric nitrogen to form a protective barrier several centimeters thick around her body. This compressed nitrogen shield blocks physical assaults, including bullets. Offense Armor also offers limited offensive utility: Kinuhata can lift heavy objects or deliver potent strikes using dense nitrogen masses, though its effective range extends only centimeters from her palms. She carries a liquid nitrogen canister as an emergency countermeasure against environments depleted of nitrogen, such as during fire attacks. Her background involves the Dark May Project, an experiment forcibly implanting portions of Accelerator's thought patterns into subjects to boost their powers. This procedure altered her personality, replacing potential expletives with the verbal tic "super" (超, *chou*). Originally speculated as an atmospheric control-type esper, her ability evolved into Offense Armor through the project. Item disbanded Dark May and recruited her, framing fellow participant Kuroyoru Umidori for the researchers' deaths. Kinuhata expressed gratitude for avoiding dissection or transfer to another project called Produce, hinting at potential origins as a Child Error. Kinuhata is twelve years old with short brown hair styled in a bobcut. She typically wears a sweater dress designed to expose her thighs while preventing exposure when bending over, paired with striped socks. Her personality blends playful teasing with pragmatism; she mocks allies like Hamazura Shiage about his interest in bunny girls yet remains mission-focused. Outside combat, she enjoys B-movies and C-movies, frequently referencing titles like *Wildman N's Zombie Escape Madness* and *Saitama☆Vocal Crisis*. Her demeanor shows less volatility than fellow Item members Mugino Shizuri or Frenda Seivelun. Her chronology includes early Item operations against the rival group School. During the Battle Royale Arc, she helped locate and combat School leader Kakine Teitoku, using Offense Armor to withstand sniper fire and destroy enemy positions with anti-tank missiles. She prioritized protecting teammate Takitsubo Rikou, recognizing Rikou's tracking ability as vital to Item's survival. Later, she aided Hamazura Shiage and Takitsubo during their separation from Item, confronting adversaries like Stephanie Gorgeouspalace despite injuries. She continued participating in subsequent dark side operations, including events leading to the "Mugino Family Arc". Kinuhata's development highlights fierce loyalty, particularly to Hamazura and Takitsubo. She encouraged their departure from Item for their safety, masking concern with insults about their perceived uselessness. Her interactions with Hamazura evolved from teasing to mutual reliance, evident during stakeouts involving Frenda's sister Fremea. She maintained involvement in Item's activities across multiple light novel volumes, culminating in the "Mugino Family Arc" in 2025.