Vivy, better known within the series as Diva, is the main protagonist of Vivy: Fluorite Eye's Song. She is an android that possesses very long blue hair with an ahoge, blue eyes, and on the left side of her neck a glowing circle with an inverted triangle that is indicative of androids within the series.
Diva is a songstress AI and was the first autonomous humanoid AI. She was given the mission to make everyone happy through her singing, though she struggles at grasping how to accomplish that. Diva's first fan, a young girl named Kirishima Momoka, gives her the nickname Vivy after the princess in a children's picture book who looks like Diva. Shortly before Diva's first birthday she meets the future AI Matsumoto, who takes control of the body of the teddy bear that Momoka gave Diva as a birthday present.