A daughter acuses her mother for killing her boyfriend but was it really the mother who did it or was it someone who has always been there

Six thousand years before Sora and Shiro were even a blink in the history of Disboard, war consumed the land, tearing apart the heavens, destroying stars, and even threatening to wipe out the human race. Amid the chaos and destruction, a young man named Riku leads humanity toward the tomorrow his heart believed in. One day, in the ruins of an Elf city, he meets Shuvi, a female exiled “Ex-machina” android who asks him to teach her what it means to have a human heart.