Can a computer ever replace a human being? Minoru Kokubunji built Yuzuki to replace his sister after her passing. While Yuzuki certainly feels like a sister to Minoru, the more time he spends with her, the more he loves her for who she is. Chi was also built as a substitute family member. Back then she was known as Elda, and she and her "sister" Freya were built to be the daughters of their creator and his wife. They behaved and looked like real children, and they even had the ability to love. But something went wrong - very wrong. Now Chi must find her "someone just for her" before an even worse disaster strikes.
