Moarida

Moarida is the femslash ship between Merida and Moana from the Brave and Moana fandoms.

Canon
Moana and Merida are both characters from the same company, Disney. However, they're from different universes. Moana is part of the universe from the movie of her same name, Moana. While Merida is from the Brave universe. Although they never met each other in their respective universes, they did meet in canon in the Ralph Breaks the Internet movie. When Vanellope Von Schweetz gets to meet all Disney princesses in the movie, Merida doesn't get to say much until the very end. When she does, she confuses Vanellope with her accent. So she turns to Moana, who is staring at Merida with a fond smile, and asks her "what did she say?" Moana replies “we can’t understand her” but while saying that, she still didn’t stop looking at Merida with a smile.

Fanon
is a relatively rare crossover ship. Most fans tend to ship Merida with the characters from her most popular crossover ship, The Big Four. And as for Moana, her most popular ships are her friendship with Maui and her ship with Ariel from The Little Mermaid.

Fans of this ship started shipping these two characters due to the many similarities they found between the two. Since the two of them are part of what's considered the "Revival Era" of Disney, fans noticed that the two, often considered "princesses," ignore many traditional gender roles. For example, fans of the ship often cite the fact that the two of them have no love interests. One of the main conflicts in Brave is that Merida doesn't want to get married. In Moana, a possible love interest isn't even introduced. The only other major male character in the film, Maui, is presented only as a much older friend and mentor to Moana.

This point is constantly portrayed in fanworks, specially in fanfictions, where the two girls meet in modern settings. Usually, the two of them are either already single, or set on remaining that way, since they haven't been presented with the possibility of finding love in someone of their same gender. In other fics, for example, they're even forced to marry men, and end up deciding to run away together.

Secondly, their main motivations are related to their personalities and interests rather than their gender. For instance, Merida uses her talent and love for archery to beat all the boys and "win her own hand" when her parents host an archery contest with marriage to Merida as the prize. Similarly, Moana is infatuated with the ocean, and it's her connection to it that sets the entire story into motion. Because their motivations are internal rather than external, they affect their storylines and make them both active characters in their stories.

This is also portrayed in many ways through fanworks of the two together, mainly fan edits, where they meet in either Merida or Moana's universes and they find a common passion, like the ocean, or share both their passions together.

Fandom
FAN FICTION