In June 2008, planning began on the next VOCALOID2 vocal for Internet co at that time planning began before Gackpoid was yet released, but there was nothing solid at this stage about GUMI.
Megpoid was voiced by Megumi Nakajima and released on June 26, 2009. It comes with three sample VSQ files, "Happy Birthday," "Be MYSELF", and "Hitori Yurari." "Be MYSELF" is an original song by Nakajima.
GUMI was designed to be a professional voicebank of good quality and is the voice of a professional singer. She was sold as a faithful CV portrayal of her provider Megumi Nakajima, so therefore was intended to have a air of realism about her voice.
Vocal traits as noted:
She has soft cutesy voice with a tense tone.
She has a large vocal range and is considered relatively easy to tune.
Her voice is raspy, however, this can be removed if a user does not want her raspiness.
Adjustments of GEN won't impact the voice as much as some other vocals and will remain relatively the same between the range -32 and 86.  This makes her harder to get tones out of her voice, compared to other VOCALOIDs such as SF-A2 miki or Megurine Luka.
Her pronunciations are of a good quality and she has smooth vowel sounds compared to other Japanese VOCALOID2 vocals.
The Megpoid software has some notable traits about some phonetics which made her easier to use against other VOCALOIDs released at the time. GUMI speaks "カ" ("ka") related lines of speech with no problems, "マ" ("ma") lines (which are the weakness of Hatsune Miku) are spoken well as well. Her "サ" ("sa") related lines do not collapse like they do with Megurine Luka. However, she has a habbit of speaking "タ" ("ta") as "ダ" ("da").
Like many native Japanese speakers, Megpoid does not have the phoneme [z] and [Z] in the phonetic system and requiring beung are replaced by [dz] and [dZ] as well as Gackpoid.
Software issues as noted:
According to the update for VOCALOID 3 Megpoid - Native, VOCALOID 2 Megpoid also had a number of background nuisances that affected her overall quality. She does not take to adjustments of volume too well and her vocal will start to suffer, causing a noise to occur. The noise loop ends at G3 and GEN 40, results which hit the Ground noise area are regarded a Low Quality.