Meroie became Hamu's guardian ten years ago after his mother is killed trying to protect their village against Captain Joke. She started to take care of Hamu when she meet Monkey D. Luffy and Roronoa Zoro. At first, she does not trust them because they are pirates, but later, she trusts them enough to help Luffy get to the Mountain of God. She does not care who stops Joke, no matter how foolhardy.
When she was pushed away from Zoro for safety while Zoro is fighting against the massive crustacean monster, she seemed attracted to his kindness and blushingly helped him due to the relief felt from the defeat of the giant crustacean. However, it turns out Sanji kicked it with a final blow, but still blushes at Sanji when he asks her out to dinner, much to Zoro's annoyance.
After the defeat of Captain Joke, the Straw Hat Pirates bid farewell. Hamu asked Meroie if she asked for their names but she replied that it was not important, because they are just a bunch of pirates.