Kaina Tsutsumi is a tall, athletic woman with a striking yet graceful appearance. She has a strong, curvy build, fair skin, and light purple eyes with white pupils that tilt inward. Her short indigo hair is streaked with pink and styled to chin length with uneven bangs that frame her face in side tails. When using her Rifle Quirk, faint smoke often rises from her right elbow.

Before joining the Hero Public Safety Commission, Kaina had longer, messier hair and a softer look, wearing a sailor-style school uniform. As a Pro Hero, she tied her longer, streaked hair into a high ponytail and wore a dark sleeveless jumpsuit with green armor plates, a utility belt, and a blue scouter over her right eye. After escaping Tartarus, she switched to a dark violet turtleneck dress with a long skirt, yellow accents, and a large utility belt carrying her ammunition. Following her explosion injury caused by All For One, Kaina’s face and body became scarred and bandaged. Eight years after the war, she is shown with longer hair, living quietly in retirement.

Kaina Tsutsumi is a disciplined and determined woman who will do whatever it takes to complete her mission. She is cold and ruthless toward her enemies, willing to harm anyone who stands in her way, as shown when she threatened Izuku Midoriya during their first encounter. Despite her hardened demeanor, Kaina has a more relaxed and cheerful side and shows remarkable courage, remaining calm even in the presence of All For One.

In the past, Kaina was an idealistic young hero who believed in justice, but the Hero Public Safety Commission exploited her skills, forcing her to assassinate criminals and corrupt heroes alike. The constant bloodshed broke her spirit, and she grew disillusioned with the hypocrisy of Hero Society. Realizing that even children admired a system built on hidden violence, Kaina snapped and killed her superior. Though she initially sided with All For One out of resentment toward the Hero system, her battle with Izuku rekindled her belief in true heroism. Inspired by Izuku and Hawks, she chose to fight for what’s right again, risking her life in the Final War to aid the heroes. Even after being pardoned, Kaina decided to stay in prison, preferring to observe how society changes under the new generation of heroes.

Kaina Tsutsumi is an exceptionally skilled and powerful fighter, once regarded as one of the Hero Public Safety Commission’s most elite assassins. Her abilities earned her recognition from All For One himself and fear from even top heroes like Hawks. Known as a “sniper rifle in human form,” Kaina’s precision and lethality made her a legend among heroes with long-range Quirks. Her extensive training under the Commission honed her combat, stealth, and tactical abilities to a level that made her one of Japan’s most dangerous operatives.

As the nation’s finest marksman, Kaina’s shooting accuracy surpasses that of any other hero, including Snipe, whose Quirk specializes in ranged combat. She can hit targets over three kilometers away, even in the dark or during heavy rain, without the need for a scope. Her keen eyesight, sharp reflexes, and agility allow her to shoot accurately while in motion or even aiming backward. Beyond her combat skills, Kaina has remarkable stamina—she survived a devastating explosion and remained conscious long enough to pass on critical information to the heroes. Even while suffering from unhealed wounds, she continued to fight, demonstrating her unmatched resilience and determination.