Sora's Owner (usually refered to as お姉ちゃん, onee-chan, in Japanese) is an important character in Toro and Friends: Onsen Town.
She is the caretaker of Sora, and likely the most key figure of the well-being of Amatsu-Sora.
Her actual name is never revealed: she is only called "my owner" by Sora and "Sora's Owner" by other characters.