Tsubaki Kurogane

Short in stature, Tsubaki has large pink eyes set under thick brows and fair skin. Her straight brown hair reaches her lower back, gathered into a high ponytail fixed by a headpiece bearing two pink flower-shaped beads, with cropped bangs and chin-length strands framing her face. She wears traditional samurai dress: a white robe trimmed in pink at the collar and sleeves over a turtleneck, shin-length pink trousers, black leggings and socks, and straw sandals, with black guards shielding her forearms. A sword rides at her hip, its hilt wrapped in black cloth and its scabbard tipped like two arrows pointing opposite ways. For travel she throws on a pink cloak and a wide bamboo hat.

Strikingly mature for her years, Tsubaki is disciplined, driven, and all business, devoted to the old samurai ways and to honoring Mifune's wishes. That single-mindedness can tip into arrogance. Polite and even deferential toward superiors, she turns condescending with nearly everyone else, at first dismissing modern shinobi as sloppy and treating her posting to a ninja squad as a mere obligation. Watching her teammates put themselves on the line for one another softens that view, and over time she comes to respect what Konohagakure offers while admitting that the Land of Iron's reverence for tradition also holds it back. Beneath the poise runs a competitive streak and a few childish quirks: she is smitten with modern food, fries above all, and works hard to hide the delight. Losing gnaws at her even in team efforts, and she is keen to prove a samurai can stand against any shinobi, aiming to climb the ranks and lift up her homeland.

Back in the Land of Iron, Tsubaki trained under Mifune beside a senior pupil named Sazanka, whom she admired and often sparred with. A tournament promised its champion the right to inherit the blade Kurosawa upon Mifune's retirement, and Tsubaki reached the final against Sazanka. Though he dominated much of the bout, she seized a single opening to win. The defeat broke him: he cut down the disciples who tried to stop him from seizing Kurosawa by force and fled as a wanted man, leaving Tsubaki to carry the guilt.

Her transfer to Konohagakure comes after Sumire Kakei leaves Team 15 for the Scientific Ninja Weapons Team, and the Seventh Hokage asks the Land of Iron for a stand-in. Unimpressed by the village's loose discipline, she meets her squadmates: Wasabi Izuno, Namida Suzumeno, and captain Hanabi Hyuga, and keeps her distance, until she watches Wasabi and Namida risk themselves against a wanted criminal and steps in to finish the fight, her quickdraw swordsmanship making short work of them. Trained by the Land of Iron's own general, she rates at chunin level and had already downed two Bingo Book fugitives. She wields precise strikes, quick-draw cuts, dual-blade work with her scabbard, and a chakra-fed tornado that scatters groups of enemies, backed by sharp misdirection and hand-to-hand skill.

When the squad's results slump, Tsubaki pushes Wasabi and Namida to compete against one another, a scheme that backfires until a rescue mission teaches her that cooperation, like the surprising mix of a burger and fries Boruto shares with her, wins the day. She later helps Denki test a radio experiment, attends the war memorial, and enters a revived Chunin Exam to prove a samurai's worth, clearing the written test and a Forest of Death rescue to reach the finals. A letter recalling her home to a leadership post thrills her, but after a hard-fought loss to Denki and his Lightning Release Suit, she chooses to stay in Konoha, feeling she still has much to learn. Her deepest reckoning comes when a mission against merchant-raiding bandits reveals Sazanka among them. Unable at first to raise her sword against her old friend, she is spurred on by her teammates and finally cuts him down, earning his dying respect.