Other names: 櫻桃 (Chinese)
Gender: Male
Age: 14
Height: 156 cm (5'1.4")
Weight: 47 kg (103 lbs)
Favorite genre: pop dance and rock / pop-pop songs - enka
Good range: F3 - C5
Character items: Banana, road-roller (shared item with Rin Kagamine)

Aged 14, Len is twin vocals with his sister, Rin Kagamine. They can be portrayed however (siblings, lovers, mirror images, etc.), depending on the person viewing them or the song.

As a character from the second installment of Crypton's Vocaloid Character Voice Series, he is voiced by Asami Shimoda.

Released on December 27, 2007, Kagamine Rin/Len is the second installment of the Vocaloid2 Character Vocal Series. Their family name was chosen by combining "kagami" (鏡, mirror), "ne" (音, sound); their given names of Rin and Len were said to be based on "right" and "left" according to Asami Shimoda. She later confirmed in an interview after the Append release that the names were based on Ken and Rin from Hokuto no Ken, derived from a discussion about names that were familiar from her childhood.

According to Vocaloid's official blog, the package includes two voice banks: one for Rin and another for Len, both provided by the voice actor Asami Shimoda. Despite the double voice banks, the package still sells at the same price as Hatsune Miku.

He has multiple cameo appearances in anime-- (Zoku) Sayonara Zetsubou Sensei, where the two (in line, recolored to blue and red) try out to be the voice of Meru Otonashi; Hyouka, in the form of a cosplayer (with brown hair ); Shinkansen Henkei Robo Shinkalion alongside the other Crypton Vocaloid voicebanks.

Alternative names/personalities:
Aku no Musume: Allen Avadonia/Servant of Evil
Akujiki Musume Conchita: Pollo
Kokoro: Otsu
Shuujin to Kamihikouki: Number 420