Kaguya

Kaguya ia a mysterious girl who was washed ashore the island of Wyndaria one day after a great storm. She has lost her memories and along with them, her emotions. Soon after the encounter with Rick, pirates from her world came after her seeking the special spirit stone that is worn around Kaguya's neck.

[Spoiler] It is reveled in episode 10 that she is from a parallel universe. [/Spoiler]

(Source: Wikia)