Adelle Bascùd

Anaguma is a character that appears in the fourth movie, Dead End Adventure. She was the assistant to the boiler man, Biera (whom she calls 'Grandpa') on board Gasparde's ship. She was thought to be a boy due to her tomboyish appearance, personality, and voice (which is actually her normal voice). She's stubborn, but means well.

Once Biera was stricken sick, Anaguma desperately begged Gasparde to help him. Gasparde made a deal with her that if she could kill a pirate, she would be considered his crewmate and he would help her 'grandpa'. She quickly left the ship to do just that and stowed away on the Going Merry, thinking it was the weakest ship. She quickly finds out otherwise when she tries to kill Zoro. Despite this, the Straw Hats took care of her and taught her a life-lesson.

During the race, the Eternal Pose that was supposed to point to their goal (Partia) was revealed to be a fake. Luffy suspects Gasparde, whom he has met and despises, to be the culprit. Anaguma supports him on his claim and reveals why she tried to kill them. She asks the crew to help rescue her 'grandpa', to which all (except Usopp) agrees to. Through Nami's guidance and Chopper's nose, they reach Gasparde's ship. Once there, she tells Biera what she has learned from the Straw Hats: value life no matter how bad it gets, and good things will eventually happen. Biera stays behind so he could overload the boiler and blow up Gasparde's ship. When Sanji reveals this, she begs them to turn back, Zoro knocks her out, revealing her gender when her cap falls off and her hair spills out.

After Gasparde is defeated, it is revealed through Biera to Shuraiya Bascùd that he rescued a little girl from a river eight years ago. The girl could only remember her name: Adelle Bascùd; Shuraiya's sister whom he thought was dead. Despite some awkwardness at first, she comes to accept her brother, seeing what a good man he is by how he protected Luffy's treasured hat. The Straw Hats manages to get to Partia but are pursued by Marines before they could reach land and claim their prize, leaving Adelle with her brother and 'grandpa' behind. Shuraiya promises to start a new life for them.

Trivia

 * Chopper seems to have known her gender the entire time.
 * Anaguma, her nickname, means "badger".
 * The order of her and her brother's names is different from the usual order of character names in One Piece. For them, the given name comes before the family name, causing an inconsistency.