'Kagamine Rin/Len V4X' was released for VOCALOID 4 on December 24, 2015. This allowed for a multitude of cross-genres that the two could now sing along to, while still sounding natural.

For Rin, 'Power', 'Warm', and 'Sweet' were included while Len had 'Power', 'Cold', and 'Serious'. In 2010, 'Kagamine Rin & Len Append' was released which provided additional styles of vocalization. those who purchased the original version were able to claim the updated 'ACT2' until September 2008. The software was released on Decemand sold around 20,000 copies.ĭue to numerous complaints about how difficult it was for producers to compose music using the twins, an independently package 'ACT2' was released. Following Crypton's concept and direction, Rin's design was the first to be illustrated, followed shortly thereafter by Len. They were the second release in the 'Character Vocal Series', which included other popular VOCALOIDs Hatsune Miku and Megurine Luka. Rin and Len were initially developed by Crypton Future Media using Yamaha's VOCALOID 2. Shimoda has said that she sang within her chest for Len's voice and sang at the top of her head for Rin's voice. Their surname, Kagamine, uses the two Japanese kanji characters '鏡' (mirror) and '音' (sound). Rin’s name along with her twin brother Len's are derived from the concept of 'left' and 'right', as in stereophonic sound. As with many other VOCALOIDs, they have performed in live concerts around the world using proprietary projection technology. They use the VOCALOID 2 and VOCALOID 4 singing synthesizing technology and are both voiced by Asami Shimoda. Kagamine Rin and Kagamine Len are VOCALOIDs developed by Crypton Future Media.

Vocaloid 4 hatsune miku