Kagamine Len is a Vocaloid developed and released in 2007. He's the twin of his sister, Kagamine Rin. He's fourteen years old, has blonde hair and blue eyes, and wears a mostly yellow, black, and white Japanese sailor uniform. Len is very outgoing. He can be described as hyperactive and optimistic at first, but can be kind and attentive when given time to open up. He has a very strong relationship with his sister, Kagamine Rin, and cannot go anywhere without her.