Kumi was intentionally designed to resemble the popular Vocaloid character "Hatsune Miku", both in name and appearance. Initially intended to be a prank to fool people, she has grown into her own unique character.

Her voicebanks and character ("Hitsune" meaning "Brushstroke Sound") feature a theme of writing tools and calligraphy. She can be referred to as her full prank name "Hitsune Kumi" or simply "Kumi".
 
Kumi has no canon age or personality.  It is left up to the user's interpretation!