Tashigi serves as a Marine officer under Vice Admiral Smoker. She debuted at the rank of Master Chief Petty Officer in Loguetown, received promotion to Ensign after Arabasta, and advanced to Captain during the timeskip. Her appearance features dark brown eyes and black hair, worn between chin and shoulder length and often pinned up post-timeskip. She bears an uncanny resemblance to Zoro's deceased childhood friend Kuina and consistently wears rectangular glasses with red frames. Pre-timeskip attire included short-sleeved shirts under a white-trimmed blue coat, while her post-timeskip outfit consists of a floral shirt, blue capris, pink gloves, boots, and a pink Marine coat, reflecting the author's evolving art style.
Notably clumsy despite her swordsmanship, her mishaps frequently draw Smoker's frustration. She possesses deep knowledge of katanas, carries a Meito field guide, and aims to confiscate renowned swords from those she deems unworthy. Her combat approach is recklessly brave, leading to defeats against opponents like Nico Robin and Trafalgar Law. Stubborn in defeat, she demands rematches when perceiving disrespect, particularly against Zoro. Her sense of justice mirrors Smoker's unconventional views, prioritizing moral integrity over strict Marine protocols. This allows cooperation with pirates like the Straw Hats when necessary, as seen during Arabasta and Punk Hazard conflicts. She demonstrates modesty in attire and discomfort with bodily exposure, reacting strongly to situations involving physical vulnerability.
A childhood passion for swords led to her Marine career. In Loguetown, she interacted with Zoro without initially recognizing him as a pirate, later developing a rivalry focused on his possession of the Meito Wado Ichimonji. Post-timeskip, she commands Unit 01 of the G-5 Branch. Her subordinates openly admire her, using informal terms like "Captain-chan," yet respect her leadership and follow her into dangerous missions. She prioritizes their safety, even withholding painful truths like Vergo's betrayal to protect morale.
Her abilities center on swordsmanship, wielding the katana Shigure and employing techniques like Kiri Shigure. She trained in Rokushiki's Soru (Shave) technique for high-speed movement and can utilize Armament Haki to enhance attacks and defenses, though her Haki mastery remains underdeveloped. Her combat effectiveness is sometimes hampered by recklessness and lapses in situational awareness.
In the film *One Piece: Stampede*, Tashigi participates in the SWORD unit's mission led by Monkey D. Garp to infiltrate the pirate island Hachinosu and rescue Koby from the Blackbeard Pirates. During this operation, she confronts the former Marine Admiral Kuzan (Aokiji). She escapes Hachinosu alongside SWORD members after Garp sacrifices himself to ensure their retreat, continuing her commitment to protecting comrades despite personal cost.
Key relationships include a mentor-protege dynamic with Smoker. He frequently reprimands her clumsiness but trusts her judgment and combat ethics, involving mutual respect despite tensions over tactical decisions like her willingness to negotiate with Law to save others. Her interactions with Zoro are defined by rivalry and unresolved tension stemming from her resemblance to Kuina and her desire to claim his swords. She experiences conflicted alliances with Straw Hat members like Nami during cooperative efforts and Sanji, whose unwavering protection despite opposing affiliations causes her discomfort. She maintains a protective role toward the Punk Hazard children, ensuring their medical treatment post-Caesar Clown's defeat.