Kairi's Grandma

Kairi's Grandma was an elderly woman who resided in Radiant Garden and presumably has a close connection to Kairi.[1] She is seen to encounter Aqua in Kingdom Hearts Birth by Sleep, the Keyblade warrior having previously rescued her granddaughter. At the Hollow Bastion library, she related to a young Kairi a story about the light and the birth of the darkness coveting the light. Thanks to Kairi's heart being transplanted into Sora during the destruction of Destiny Islands, Sora was able to access Kairi's apparently lost memory of her grandmother telling her the story of light and darkness. Later, after Kairi is restored to completion, Sora, upon meeting Kairi in the Underwater Cavern in Traverse Town, acknowledges that there is a deeper meaning to this story, and stated that it was "more than just a fairytale".

Kingdom Hearts Birth by Sleep
Kairi's grandmother first appears in terms of story chronology in Kingdom Hearts: Birth by Sleep. She finds Kairi after Aqua and Mickey saved her granddaughter from a group of Unversed. While walking away, Kairi pleads her grandmother to tell her her favorite fairytale about the light and the darkness, with Aqua listening in the background.

Kingdom Hearts
Kairi's grandmother only appears when Sora experienced Kairi's memories. In the flashback, she told Kairi a story.
 * Long ago, people lived in peace, bathed in the warmth of light.
 * Everyone loved the light.
 * Then people began to fight over it.
 * They wanted the light for themselves.
 * And darkness was born in their hearts.
 * The darkness spread, swallowing the light and many people's hearts.
 * It covered everything, and the world disappeared.
 * But small fragments of the light survived... in the hearts of children.
 * With these fragments of light, children rebuilt the lost world.
 * It's the world we live in now.
 * But the true light sleeps, deep within the darkness.
 * That's why the worlds are still scattered, divided from each other.
 * But someday, a door to the innermost darkness will open.
 * And the true light will return.
 * So, listen, child.
 * Even in the deepest darkness, there will always be light to guide you.
 * Believe in the light, and the darkness will never defeat you.
 * Your heart will shine with its power and push the darkness away.
 * Do you understand, Kairi?