Nano

Her appearance is similar to that of a child as she is often described as "young" and "small". She has short dark hair that stops at her neck and her height is petite compared to other androids. She was first seen wearing a ribbon so that she could be distinguished by Milo as his 17th birthday present. She is often described as 'lovely' and 'cute' which was how Dr. Maddie Ahn wanted her to be.

(Source: Nano List wiki)