Childish, cute, non-human, cant speak normaly because her words are only "Nyu" and even her nickname which was given by Kouta is Nyu. Sometimes she can be really dangerous because of her hidden, secret, and REAL personality called "Lucy" who is a murderer and yandere because of her dark past with Kouta and his family and where she was locked at a military base's prison but she escaped from there. As long Nyu doesn't get injured, then Lucy wont take the control over her and kill peoples.