Keychain | Vocaloids | Kagamine Rin

Kagamine Rin & Len (鏡音リン・レン), codenamed CV02, are Japanese VOCALOIDs developed and distributed by Crypton Future Media, Inc., and were initially released in December 2007 for the VOCALOID2 engine. They are the second set of vocals for Crypton's Character Vocal Series and are both Character Voice VOCALOIDs. Their codename "CV02" means "Character Voice 02".

The development of the Kagamines began when Crypton formulated the concept of making a pair of female and male voicebanks. The first idea was for two voices of a girl and an identical male of the opposite gender, just like twins.

Crypton originally had the intention of distributing them as twins, but this was not adopted. Crypton stated that they approved of the many different interpretations of Rin and Len's relationship that they saw in different works. Crypton's final announcement was that the Kagamines were neither siblings nor lovers. During their Append's production, Wataru Sasaki (aka. Wat) described them as two bodies with one soul. Wat also said that the Append boxart makes the pair seem like twins, due to the foetal position they were in.