Ariel

Ariel is a character from the Kingdom Hearts games, living as princess in the sea world Atlantica. She is originally from the Disney movie The Little Mermaid.

As a person, Ariel is very curious about the dry land and often dreams to visit other worlds, which her father forbids her to even think about it.

Kingdom Hearts
Ariel makes her debut in Kingdom Hearts. She meets Sora, Donald and Goofy when she is running away the Heartless with Sebastian and Flounder. When she hears Goofy talking to her father about a Keyhole, she decides to help them find it and manages to find the crystal, that resembles her father's trident, that has the power to reveal the Keyhole. King Triton arrives in time to destroy it.

The sea witch Ursula lures her into helping her steal the trident from her father, which she does and almost makes a huge mistake. With Sora's help, they defeat the sea witch Ursula.

In this game, Ariel is able to use all kinds of magic that Sora has learned over the course of his journey (excludes summoning magic).

Kingdom Hearts: Chain of Memories
In Kingdom Hearts: Chain of Memories, she serves as a memory of Sora.

Kingdom Hearts II
In Kingdom Hearts II, she has an unusual role, as Atlantica sets a musical stage about Ariel and Prince Eric. Like the original movie, she saves the prince from drowning and takes him to shore, there she sings to him until he awakes.

Unable to forget about the prince, she falls into deep depression, and so Sora and the others decide to help her. When her father finds out that she has fallen in love with a human, he tries to make her forget about him by destroying the statue made with his face. But then Ursula reappears and makes a deal with her; to make her human for three days in exchange for her voice. In addition she must make the prince kiss her willingly before sunset on the third day, otherwise she will become hers forever. Despite the hardship, she signs the contract and finally gets to meet Eric in person, although he does not recognize her.

On the third day, Ariel gets her voice back with Sora's help, and they all battle the sea witch while performing a musical: Ursula's Revenge. Once Ursula is defeated, Ariel reveals to Eric that she is a mermaid and says goodbye to him, but he does not change his feelings about her. Seeing how much they are in love, King Triton finally gives in and lets his daughter be with a human prince.

In the ending credits, Ariel is seen in human form and marries Eric.