The Survey Corps Pirates!

(Reader's full name) was a simple-minded 14-year-old girl who could be unbeatable at times. She works as a "pirate thief", a thug who wittedly steals a pirate crew's loot without getting caught and has her loot sold within the black market.
Right after her beloved hometown was attacked and raided by an unbeatable pirate team "Survey Corps", (Reader) then decides to have the treasures taken back and to steal some of their loot. But it seems like her luck has run out, for just as she was just about to hop off board with her loot, her scent was taken in by Mike Zacharias, the pirate captain's childhood friend, and was locked up, thus giving her no chance to escape.
Fortunately, Captain Erwin Smith's having a great need of new crew members, and asks (Reader) to join. Levi Ackerman, the second-in-line for being captain, then beats her up and forces her to be a crewmate (which caused for [Reader] to hate his guts, and yet to form a little respect for him). The poor, captive girl then accepts the offer, and become's the crew's first-ever female shipmate.