The keytar Len is often featured holding in merchandise is a YAMAHA KX5. Their leg features were designed to mimic speakers. Rin was the first of the Kagamines to be illustrated and Len was made to match her, following Crypton's concept. KEI was not given any further direction, as he had already drawn the art for the first release in the Character Vocal Series, Hatsune Miku. KEI was given a concept by Crypton that included Rin and Len's approximate ages, as well as the idea of them being 'mirror images' and, like Miku, androids. Their codename of 'CV02' means 'Character Voice 02'.

Their surname was derived from the developing code combining Kagami (鏡, mirror) and Ne (音, sound). 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. Their given names of Rin and Len were said to be based on 'right' and 'left' according to Asami Shimoda. When the Kagamines were being recorded in 2007, their names had not yet been decided. Wat also described that the Append boxart makes the pair seem like twins, due to the fetal position they were in. Wat) described them as having one soul between the two of them. During Append production, Wataru Sasaki (aka. However, Crypton's final announcement was that they were neither siblings nor lovers. After seeing many works that depict their relationships differently, Crypton announced in a magazine interview that those would meet their ideal. Ĭrypton had the intention to distribute them as twins, but this was not adopted. The first idea was for two voices of a girl and her mirror image of the opposite gender, just like twins. The development of the Kagamines began when Crypton formulated the concept of making a pair of female and male voicebanks.

Vocaloid 4 rin and len