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The Kagamines as characters are marketed as mirror images, it is unknown if Crypton's intention was for the voice bank to be one in the same or individuals (regardless of having different names) since it is Rin that was the main purpose for their fourth Vocaloid release. From the interviews available there seems to be no official mention of genderbending when it comes to Rin and Len.

The fandom chooses to view the Kagamine's as two different characters (commonly siblings) and have created genderbend versions of the Kagamine Rin and Len.