Len: Hey! Hey! Are you ready?
Rin: OK, go!

Kagamine Rin & Len (鏡音リン ・レン) are Japanese VOCALOIDs released in December 2007 for the VOCALOID2 engine, developed and distributed by Crypton Future Media, Inc.. There has since been numerous installments such as additional voice banks dubbed 'Append' as well as an upcoming upgrade to the VOCALOID3 engine which is said to include an English vocal release. They are the second set of vocals for Crypton's VOCALOID Character Vocal Series.


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 her mirror image of the opposite gender, just like twins. 

Crypton had the intention to distribute them as twins, but this was not adopted. After seeing many works that depict their relationships differently, Crypton announced in a magazine interview that those would meet their ideal. However, Crypton's final announcement was that they were neither siblings nor lovers.  During Append production, Wat described them as having one soul between the two of them. During the boxart for the Append, Wat described it as making the pair seem like twins, due to the fetal position they were in.


When the Kagamines were being recorded in 2007, their names had not yet been decided. 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 name itself was based on the names of Ken and Rin from Hokuto no Ken, derived from a discussion about names that were familiar from her childhood.

Their surname was derived from the developing code combining Kagami (鏡, mirror) and Ne (音, sound).


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. 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.

Rin was the first of the Kagamines to be illustrated and Len was made to match her, following Crypton's concept. Their leg features were designed to mimic speakers. The keytar Len is often featured holding in merchandise is a Yamaha KX5, from which the design of both Kagamines take certain elements.

When Rin and Len received a new set of vocals during their Act2 release, KEI took the opportunity to fix art flaws in their artwork.

Kagamine Rin's introduction artwork:

  • Rin has "Act2" on her arm under her "02" tattoo.
  • Rin's top was changed in the introductory image between versions around the armpit area. Frills were added to the bottom of her top in Act2.
  • Her shoulder was not correctly drawn in the original version.
  • All the yellow bands on her outfit were made bigger on Act2.
  • Her fringe was made thicker above the left eye.
  • In Kagamine Rin's artwork, her left knee was thicker and her right leg was too short. Kei corrected this in her Act2 version. Her right leg position changed and so did the position of her left foot.
  • Forearms have been shortened in Act2.
  • The cyber-on-normal clothing design on their detached sleeves was changed from a green bar to a blue one.

Kagamine Len's introduction artwork:

  • Kagamine Len has "Act 2" on his headphones.
  • The cyber-on-normal clothing design on the detached sleeves were changed from a green bar to a blue one.
  • His fringe was reshaped, other strands were adjusted as well.
  • Len's face, particularly around the cheekbones, was reshaped.
  • His left knee had a minor tweak.

Boxart changes;

  • Kagamine Rin's leg position was changed in their boxart so it was lifted off the ground, the only way the previous position would have worked was if her leg were deformed or broken.
  • Rin's body itself compared to the length of her legs is shorter than in the original boxart, while the legs are longer.
  • Kagamine Rin's knee is rounded instead of sharp.
  • Both had the cyber details changed on their detached sleeves.

For their appends, Wat wanted them to have a sense of transparency with their design. In clarification to what he meant by this, he stated the "transparency" was in reference to their hearts.

Their Append design and the official illustration were made by オサム (osamu).

Continuing the tradition of the Item War Internet Meme, many items were proposed for the pair. In the end, Len's item was a banana, because his hair was commented to resemble a bunch of them, while Rin's item was an orange since her bow gave the impression of orange leaves. Before her release, Rin had the road roller assigned to her by accident in a video that received many views suddenly on December 1, 2007. Kagamine Len had yet to be revealed at the time of the road roller meme.



The Kagamines were marketed as "2 vocals for the price of 1" and were aimed to catch the interest of the growing Vocaloid fandom. Unlike Hatsune Miku, they were not an immediate hit, failing to meet marketing expectations despite receiving the same level of promotion as Miku was receiving at the time of their release. After the release of their "Act2" voicebanks sales picked up steadily and the Kagamines eventually became one of the more heavily marketed VOCALOIDs, though have never met the marketing strength Miku gained before them.

Good Smile Racing

See Good Smile Racing


The Kagamines have had several figurines made for them. Some are based on one vocalist and not the other; other times they both received a model, but each was released separately.

Kagamine Rin has more figurines than Kagamine Len. As well as having a standard Figma and Nendoroid figurine each, Rin has had a figurine based on the "Meltdown Hard R.K. mix" PV. She has also appeared alongside Miku and Luka in the Good smile racing figurine promotions. Pullip Dolls were released for both Rin and Len alongside Miku. Rin and Len were released as Dal's, and Miku was released as Pullip.

The pair have seen a number of Garage Kit packs as well.


They have appeared on T-shirt designs, often to promote themselves or particular albums by producers.

In 2011, Piapro held a contest with members to design Gothic Lolita clothing for VOCALOIDs, the designs were produced by the company Putumayo. Amongst the winners were designs based on the Kagamines' own attaire.

ACOS have also produced an official cosplay outfit + wig.

US Debut

The Kagamines appeared in the Los Angeles Mikunopolis concert in July 2, 2011, along with Hatsune Miku and Megurine Luka. Rin performed "Meltdown" in her Hard Rock remix outfit and Len performed 'Butterfly on Your Right Shoulder' (Ft. Rin).

Guest Appearances

In Zoku Sayonara Zetsubou Sensei a pair of Len and Rin lookalikes are seen in the waiting queue during the auditions for the role of Meru Meru, however they do not have the Kagamine's known colors.

In the anime Maria†Holic Rin and Miku appear on a scene on episode 12, which can be seen on Youtube

In the manga Comic Party, during the fair there is a person wearing Rin's ribbon and the same hairstyle.

From episode 12-16 of Hyouka, there are Miku, Rin, Len, and Luka cosplayers.


Crypton Future Media VOCALOIDs have also appeared in 2013 calendars.

5th Anniversary 

Crypton Future Media celebrated the Kagamine's 5th Anniversary, along with Megurine Luka's 4th, with a number of goodies.

Manicure Set

Rin/Len appeared on a nail varnish set along with the other 5 Crypton vocalists. The colors within the set match the colors of the VOCALOID's painted nails.

Additional information


The Kagamines were slow to gain popularity in the Japanese fandom after the backlash from their original voicebanks. In later years, although between the two of them they had gained the second-highest number of songs, they were not as popular as Hatsune Miku. Their designs have spawned many producer based derivatives.

In the Japanese fandom, Rin is the more popular of the two, with more related works than her counterpart Len. Because of KAITO's failure, male voicebanks had little demand at the time of the Kagamines' release. Len's voicebank was the only male VOCALOID2 vocal until Gakupo's release.

An independent search on Nico Nico revealed that most VOCALOIDs had less than 1,000 videos uploaded onto Nico Nico in 2011 between July 1 and December 15. The Kagamines, however, managed to gain enough views to not fall into this category. Rin received 2811 uploads while Len received 2021. Rin had the 3rd highest total views during this period of any VOCALOID with 5,327,456 views and 477,046 mylists, and Len managed 4,555,580 views and 413,901 mylists. When sorted by average, Len was third with 2254.12 views per video and 204.8 mylists (which was more than Miku’s), and Rin had 1895.22 views per video and 169.71 mylists. However, when the views were based on the more accurate mean total, Len and Rin achieved 355 views/16 mylists and 349 views/16 mylists respectively per video, ranking last among the top 6 Vocaloids. However, the Kagamine software was the only VOCALOID package to be be in all top 6 lists besides Gumi.

Their Append outsold the Miku Append during the period after their release. The Act2 package and Append secured 4th and 5th spot between them in Crypton's end of year top 10 VOCALOID sales, despite only being available for a short period of time (mostly owed, but not entirely, to pre-orders). However, in June 2011, their Append had fallen to 8th place, one place below KAITO's VOCALOID voicebank.

Google Trends "Kagamine Rin"

Google Trends "Len vs. Rin" in Japan


  • It took 25 hours (4 hours a day) to record all the Kagamine Appends.
  • Some call Rin and Len by the incorrect names "Lin" and/or "Ren". Though the romanized version of the word could be either, the English version has been confirmed as "Rin and Len" and since there is no dubbed version to contend with, the names remain the only official names in existence for the vocals. This is also backed up by the origins of their names as "R" (Rin)" and "L" (Len).
    • Note; "L" and "R" mean "Left and Right", they are the letters you find on a set of headphones (and sometimes other equipment such as speakers). Usually there is not enough space to write "left" and "right" on headphones. "L" refers to left ear and "R" is right ear.
  • On the Mikunopolis website their profile reads the following statement: "The Kagamine twins are well known for their very clear and precise vocals". Considering their history of lack of clarity and/or pronunciation problems, as well as Act 2 of the software missing a pronunciation entirely, this is a little bit of an exaggeration on the webhost's part. Also the statement, "Just with a few tweaks here and there they could sing almost any other genres as well," is somewhat questionable due to their reputation of requiring previous experience to use and often at times needing more than just a few tweaks to make them work.
  • Rin has a G-clef (Treble-clef) on her shirt, and Len has a F-clef (Bass-clef) on his. In their Append redesigns they are found on chokers rather than their shirts.
  • With a total of 10 voicebanks, Asami Shimoda is the vocal provider with the most VOCALOID voicebanks for commercial sale based on any single provider. This also makes the Kagamine package the most expansive set of vocals within the VOCALOID2 era and to date the most of any Vocaloid package. However, as individual characters, Rin and Len have only 5 vocals each and are beaten by Miku and GUMI in total number of vocals per character.
  • In piano sheet music, the bass-clef is played with the left hand, while the treble-clef is played with the right hand. It is believed that this is used for Rin and Len's names (Right for Rin and Left for Len).
  • Most people pronounce "Rin" the wrong way; Rin is pronounced as "R EE N" like the way you say "Miku (M EE KU)" or "Yuki (YU KEE)"

Notable for...

  • First and only dual voicebanks released with two "VOCALOIDs" in one package
  • First male (Len) released for VOCALOID2
  • First VOCALOIDs to be updated
  • First vocal (Len) released not to be the same gender as the provider
  • First male (Len) to be Appended


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