MEIKO SAKINE
MEIKO is a Vocaloid DTM(Desktop Music) software created by Crypton Future Media and she utilizes the older Vocaloid engine developed by YAMAHA. Her voice is based on a Japanese female singer Meiko Haigō (拝郷 メイコ, Haigō Meiko), which is steady, straightforward, and suitable for any musical genre. 
NERU AKITA
NAME INTERPRETATION:
亞北 (Akita) - Play on words from "飽きた" or "get bored."
ネル (Neru) - Also play on words from "寝る" or "go to bed."
TYPE: BOUKALOID (in Japanese, 防火ロイド or 防火LOID) - This is again a play on words. It literally means Fireproof-loid and has the same pronunciation as Vocaloid in Japanese.
PERSONALITY: A delinquent girl, but can be cool , and nice. Neru is a girl that does things her way, which is ironic, considering she is employed in a writing agency for a rate of 700 yen per hour. She also speaks in Tohoku dialect. She tends to be depicted as the anti-hero or villain to Miku. She is notably tsundere, most especially when depicted with Len or anyone she secretly likes. Deep down she has a good heart and is a secretly fun-loving person.
KAITO
KAITO is a Vocaloid DTM (Desktop Music) software created by Crypton Future Media. The voice was supplied by a Japanese male singer Naoto Fūga (風雅 なおと, Fūga Naoto )
MIKU HATSUNE
Hatsune Miku (初音ミク) is a singing synthesizer application and its female character, developed by Crypton Future Media. It uses Yamaha Corporation's Vocaloid synthesizing technology. Her voice is sampled from Japanese voice actress Saki Fujita.
