Ain

Ain is the second-in-command and vice-admiral of the Neo Marines and a former member of the Marines. She is a major antagonist of One Piece: Film Z.

When she was a Marine soldier, she fought with Zephyr and Binz against a powerful pirate that cut off Zephyr's arm. She and Binz were the only soldiers other than Zephyr to survive.

After the said pirate was promoted to the ranks of Shichibukai, it caused Z to leave the Marines out of indignation; and in loyalty, Ain resigned her position as a Marine officer, alongside Z, Binz, and Shuzo. All of them would become the founding members of the Neo Marines. She eventually fought against Shuzo for the position of second-in-command, and after a five-hour battle, when she was on the verge of losing, she strategically trapped Shuzo in the ground and threatened him with a pistol, winning the position.

Ain was commanding the Neo Marines and she was standing alongside Binz waiting for Shuzo to arrive. However, when he did not, she called him. Shuzo wanted to kill Lily's father. and Ain said that if he failed then he would suffer the consequences.

Later, Ain read about Shuzo's defeat and told Z about it shortly before their arrival on Firs Island.

Ain was first seen on Firs Island, invading it to help secure the Dyna Stones with Z and the Neo Marines. She attacked the Marines on the island and helped Z to retrieve the Dyna Stones. When Borsalino arrived, she quickly gathers the lower Neo Marines back into the ship. After Z blew up the island, Ain was seen worrying about his fate.

Ain was later seen finding Z on the Thousand Sunny, using the help of the Vivre Card. She boarded the ship, and fought some members of the Straw Hat Pirates. She easily subdued Chopper and Nami by turning them into children, and also managed to rejuvenate Robin and Brook. After Z defeated Luffy, Zoro, and Sanji, Ain returned back to their ship with Z, and was surprised when the Thousand Sunny flew away using a Coup de Burst.

Sometime after their fight with the Straw Hat Pirates, the Neo Marines reached Secon Island. Shortly after the Dyna Stones Z planted near the island's volcano exploded, Ain was seen alongside her leader as he was talking about the Grande Imbuto. They were then attacked by Luffy, Zoro, Sanji, and Usopp, who came to get Ain to return the rejuvenated Straw Hats to their normal ages. On Z's orders, Ain fought Zoro briefly, but soon interrupted the fight to evacuate the island. She was later seen aboard their ship, overlooking the island's destruction.

Ain was next seen on Piriodo, listening to the conversation between Kuzan and Z. Sometime later, the Straw Hat Pirates arrived, and she fought Roronoa Zoro one last time. She tried to keep her distances as much as she could and win by injuring him with lava rather than brute force, but Zoro proved to be too strong anyway and managed to win easily. With Ain's defeat, Nami, Robin, Chopper, and Brook returned to their normal ages. She later woke up, and showed up after Luffy has defeated Z. When Borsalino showed up with a troop of Marines and threatened to kill both the Neo Marines and Straw Hat Pirates, Z stayed back to hold them off. Ain tried to run after him, but Kuzan created a wall of ice, preventing her from getting any further. She broke down in tears, knowing that Z was surely going to meet his end. She was last seen alongside Binz, mourning over Z's grave, as Kuzan tried to console them by telling them how great a man Z was.