Aerith

Aerith Gainsborough is a character who lives in Traverse Town in Kingdom Hearts and Hollow Bastion/Radiant Garden in Kingdom Hearts II. Like most of Sora's allies, she originates from the Final Fantasy universe. Aerith is voiced by Mandy Moore in Kingdom Hearts, Mena Suvari in Kingdom Hearts II, and Maaya Sakamoto in the Japanese versions of both games. She has a particularly minor role compared to the other Final Fantasy characters. This is most likely a due to the off-hands role she played after her fate in the original game.

Kingdom Hearts
"Final Fantasy VII"

''She lost her home to the Heartless at a very young age. Beneath her gentle disposition lies a strong will and a firm sense of duty. Many are naturally drawn to her. Aerith works with Leon and Yuffie to learn more about the Heartless and the "key".''

Kingdom Hearts: Chain of Memories
''A young woman who fought the Heartless. Her calm demeanor hides an unbreakable will.''

Aerith also has a mysterious sense of truth, and is aware that Traverse Town and it's inhabitants are a figment of Sora's memory.

Kingdom Hearts II
''A young woman whose quiet eyes belie an unbreakable will. Like Leon, she met Sora while living away from her hometown, and helped him now and then on his journey.''

Now Aerith works with Leon and Yuffie to restore the town to its past splendor.

Kingdom Hearts
Aerith is encountered by Donald and Goofy on the first trip to Traverse Town, where she explains the nature of Ansem's Report, as well as the Keyblade to them. She had a few more appearences along with Leon and Yuffie. Later, she showed up in Hollow Bastion after Xehanort's Heartless dissapeared, and spends her time studying the Heartless's research in Hollow Bastion's library. Talking to her will allow Sora to learn "Curaga", the strongest cure spell in the game.

Kingdom Hearts: Chain of Memories
An image of Aerith appears, along with Leon, Cid, and Yuffie, in the memory-based Traverse Town in Castle Oblivion. At first, she, like the other characters, expresses disbelief that she seems to know Sora despite not remembering him. After speaking with Sora, however, she comes to realize that she is just a projection based off his memory of her. She and Maleficent in Riku's game are the only ones to realize this.

Kingdom Hearts II
Aerith is a member of the Hollow Bastion Restoration Committee. In Kingdom Hearts II she wears a modified version of her Before Crisis outfit, only with a red skirt instead of a green one. She helps during the battle in Hollow Bastion by healing Yuffie and presumably continues to fight against the Heartless. Aerith also assisted during the MCP rampage which she downloaded the deletion program. In the credits, she is seen sitting and looking up towards the sky. She also encourages Cloud to do what he must, and is sure that destiny will lead him back to her.