Tashigi

Master Chief Petty Officer Tashigi (たしぎ曹長 Tashigi Sōchō) is a Marine officer serving under Captain Smoker. She was first introduced when the Straw Hat Pirates docked in Loguetown, where she was stationed. Smoker, her Captain, seems to regard her as a protégé; the two work very well together and share what appears to be almost a father-daughter relationship. While adept at sword fighting, she is unusually clumsy, which tends to gets on Smoker's nerves. She is also very well-versed in katana, knowing their names and origins.

History
Tashigi's stated goal is to remove all Meitō (named swords with prestigious histories) from the hands of those who would use them for their own selfish ends. After meeting Roronoa Zoro (whom she had inadvertently helped pick new swords before she learned his name), she set out to sea with Smoker, chasing after him and the rest of the Straw Hat crew.

View On Justice
Like Smoker, Tashigi has her own view of "Justice" which differs from the Marines' own definition, and will fight for what she sees as the right thing to do. During the battle for Arabasta, Tashigi is badly wounded while fighting against Nico Robin, and bears witness to the triumph of Luffy and his crew in the name of their friends. Though association with pirates is a serious offense, neither she nor Smoker feel the need to pursue any charges against the Royal Family of Arabasta, opting instead to continue sailing the Grand Line.

Meeting of Zoro
When Zoro first saw Tashigi, he was instantly struck by how much Tashigi looks like his deceased childhood friend Kuina (so shocked that he instantly crushed Tashigi's glasses in his hand). It is a promise made with Kuina that motivates Zoro to be the greatest swordsman in the world, and Kuina left him the Wadō Ichimonji, his greatest treasure. It remains to be seen if there is a more than coincidental connection between Kuina and Tashigi.

She and Smoker haven't been seen since the two of them left Arabasta.

Trivia

 * Tashigi is 21 years old and is 170cm tall. Her birthday is October 6th. If Kuina was alive today, she would be 21 as she was two years older than Zoro.
 * In Japanese Fan Polls, Tashigi is currently the 20th most popular character.