Vocaloids (from "vocal" and "android") are music synthesizing programs based on real human voice samples and technology created by the Yamaha Corporation. Think Synthetic Voice Actor meets Auto-Tune. There are currently 45 vocaloids (Rin and Len count as one product instead of two, as do anon & kanon); and fans have created personalities for each character based on official art (some have no official art) and voice. Fans have also created characters based on official releases, such as Neru Akita and Haku Yowane.To use a Vocaloid, one simply has to type in the lyrics of the song of their choosing as well as the melody for said song, although a great deal of fine-tuning is usually necessary to have the result sound natural. Vocaloids have become so popular that an official unofficial manga adaptation, Hatsune Mix, was created, telling the trials and tribulations of the Crypton-produced Vocaloid family: Meiko, Kaito, Miku Hatsune, Rin and Len Kagamine, and Luka Megurine.Vocaloid took major steps to becoming Serious Businessnote On the Internet, anyway. Even with it extending into the real world, Vocaloid is still a niche thing, even to Japanese who identify as Otaku, with several of them not even knowing there are more Vocaloids than Miku Hatsune. Flagship character Miku Hatsune has become a fully-fledged Virtual Celebrity, with an album featuring her work (composed by synthesizer band Supercell) nearly topping the Japanese music charts at No.2, and Miku herself putting on a live concert at Animelo Summer Live 2009. (Her "live" performances involve the same tech used for the Gorillaz' live shows and the 2Pac hologram from spring 2012.)Toyota also began an ad campaign for their 2011-model Corolla, starringMiku herself; it was subsequently revealed that Toyota sponsored Miku's first overseas appearance — a live concert in Los Angeles at Anime Expo 2011.In the 2010 Concert, Rin, Len, and Luka made debuts with even better renderings. In addition, the Vocaloid song "Black★Rock Shooter" (which features said character, created by artist huke) has inspired an official anime OVA of the same name, which was produced by animation studio Ordet (ex members of Kyoto Animation) and was released on 2010. Another popular song, "Kokoro" seems to be getting its own musical. "Daughter of Evil", in turn, got its own theater play and later a manga. "Cantarella" got a musical, too. The song "Kagerou Days" and other songs related to it collectively dubbed "Kagerou Project" also experienced a burst of popularity, enough to get a serialized manga and a novel written by the song's own producer, culminating in plans to produce an anime adaptation.Miku had yet another overseas concert in Singapore during the Anime Festival Asia 2011 on November 11, 2011. In addition, during 2012's Miku Party concert, Kaito and Meiko made appearances. Starting May 6th, 2014 and going through June 3rd, Miku will be opening for Lady Gagaas a part of her ArtRave tour, performing at no less than 16 different venues.The producers cosMo, Deco27, and mothy have their own pages, as does the band supercell, the music-video-making software Miku Miku Dance and SEGA's Licensed GameHatsune Miku Project DIVA.Note: The following is only for tropes related to official Vocaloid material. For tropes on songs, fanon, and other fan works, go here.
The homepage for the Miku Corolla advertising campaign. It seems like whoever drew her doesn't like certain ideas of cuteness... Toyota changed her appearance later, perhaps bowing to pressure from disappointed fans.
Crypton's Piapro website held a contest for an official "American" Hatsune Miku design, and declared a winner (made by Exiled Artist). The contest runners indicated it would be used "in a commercial basis or in projects related to Miku's next concert"; it was eventually used in the March 9, 2012 39's Giving Day concert when she performed PoPiPo.
Breakout Character: Miku Hatsune; she was only the seventh Vocaloid ever released, and yet she gained the most popularity among the fandom. These days, you can see a significant amount of fans who know more about Miku than any other Vocaloid, and sometimes learn about the franchise from her.
SeeU, the Korean Vocaloid from the V3 series, has cat ears on her headset.
Iroha Nekomura. She has a Hello Kitty design, with a big cat helmet and little cat-eared speakers, among other things. Her surname even means "Cat Village".
Color-Coded Characters: Many of the earlier Japanese Vocaloids had one dominant, unique color associated with them (Meiko, Kaito, Miku, Rin/Len, Luka, Gakupo, Gumi); with the influx of new Vocaloids, this concept has largely been abandoned.
Color-Coded Stones: Aoki Lapis is named for the Lapis Lazuli Gemstone and has a color scheme of blue and purple.
Left-Handed Mirror: Len and Rin Kagamine, opposite-gender mirrors of each other or Half-Identical Twins (depending on who you ask). This trope is most evident in Fanon works involving these two, as their official characterizations are virtually nonexistent.
Loads and Loads of Characters: There's quite a few already and the number is only growing. And that's not even getting into the fanmades and genderbends. Note that this number increases exponentially. In 2010, the number of Japanese Vocaloids could be counted on both hands, and the number total were still easy to keep track of and to recite without issue. By the time 2012 arrived, the number had almost tripled.
Loads and Loads of Loading: The PSP version of Project DIVA games are plagued with this, not surprising since most UMD-based PSP games have long loading times. Especially if you have the DLCs installed, as it needs to check the license everytime the list of DLC items are loaded.
Lyrical Dissonance: Some of the nightmare fuel songs like "The path to eternal happiness I found it" can be misleading.
Meaningful Name: Most official and fan characters. The 'Hatsu' of Hatsune (Miku's surname) means first; she was the first Japanese Vocaloid2 character and first of Crypton's "Character Vocal Series". The 'Kagami' part of Kagamine (Rin and Len's surname) means 'mirror'; Crypton once described them as mirror images instead of being twins, although they backtracked on that. The 'Meguri' of Megurine (Luka's surname) means circulating/revolving; a reference to her bilingual capabilities. Furthermore, the 'ne' at the end of Kagamine, Hatsune, and Megurine means 'sound'. Akita Neru means 'I'm tired; going to sleep' and Haku Yowane means 'weak-willed words'. In fact, the name "Akita Neru" was coined because of the troll who created her using the phrase akita, neru ('I give up; going to sleep'), as a reaction of frustration about the difficulty of using the VOCALOID software.
Lily's voicebank was sampled from the singer Yuri Masuda. "Yuri" means "lily" in Japanese and similarly, Gakupo, voiced by Gackt (pronounced Gakuto) and Gumi, voiced by Megumi Nakajima. Utatane Piko, voiced by Nico singer Piko.
One Mario Limit: A visual variant. Any other character with big twintails of a similar color will be confused with Miku.
Opposites Theme Naming: Rin and Len Kagamine. Their names are a pun on the words "right" and "left", respectively.
Rapunzel Hair: Miku, and to a lesser extent Luka, Galaco, Nekomura Iroha, Mew, Haku and Neru. Fanartists tend to draw it even longer, to the point of it being longer than the character is tall.
With the addition of Vocaloid3 IA and her very long hair, which is comparable to Miku, it goes down to her ankles.
The Voiceless: In Project Diva F, DLC characters Yowane Haku, Akita Neru, and Kasane Teto are not given voices when in the interactive mode. They do sing, however, which is odd. Curiously enough, Haku and Neru, who were adopted as "official" characters by Crypton, do not actually have official voices, which leads to Miku and Rin users downpitching the vocals to give them some semblance of a vocal identity.
Wolverine Publicity: Miku is something of an internet sensation, and a lot of people would like her to feature in their own properties, not just as a virtual voice actor but as herself— even a minimal role will do, as long as they get to display her prominently in their advertising. An example of this would be Seventh Dragon 2020, where she appears as Hatsune Miku Type-2020.