Kuzuda Yone is an UTAUloid designed by Kurukuru Suuzi. Suuzi also provided her voice for Yone's voicebank. Yone's voice is described as sweet, feminine, and somewhat childish.
Her name Yone consists of the characters 夜 (Yo) and 音 (Ne), meaning "night" and "sound" respectively. Her surname Kuzuda consists of the characters 葛 (Kuzu), the kanji for "kudzu", also called Japanese arrowroot, and 駄 (Da), meaning "worthless" or "low-grade". Spoken aloud, her full name 葛駄夜音 (Kuzuda Yone) sounds like the phrase クズだよね (Kuzu da yo ne), meaning "Trash, isn't it?".
Yone is an oni who has lived for 312 years, but appears to be 12 years old. The mouth on her hand has no tongue so she cannot taste with it, but she can use it to store items in her body. She enjoys mischief and acting like a brat. She has very long white or grey hair and often wears a striped kimono. Her eyes (or eye?) are covered by a sheet with a single eye on it.
(Character details sourced from the UTAU wiki and Suuzi's official site)