Kagamine Len has brilliant arctic blue eyes, short blonde hair with a ponytail at the back, white headphones with yellow half-circle with two small light blue squares on each earpad, and an attached mic on the right earpad with two small yellow rectangles on the left.

Like Hatsune Miku, Len's attire is mainly based on a school uniform where he wears a white shirt with a black collar and cuffs with a yellow stripe, a black and yellow rectangle and a VOCALOID logo on the left side