galaco (ギャラ子) is a Japanese VOCALOID originally developed by Internet Co., Ltd. and YAMAHA Corporation, under the Stardust Music, Inc. name. Her update is a collaboration between YAMAHA & Stardust Music, Inc. only. She was offered exclusively as a competition prize in the VOCALOID Shop, and was initially released in August 2012 for the VOCALOID3 engine. The voice provider was revealed to be Kou Shibasaki (柴咲 コウ; Shibasaki Kō), a Japanese female actress, singer, and member of the Japanese music group, galaxias!.
Her design and original concept came about with the release of the "galaxias!" musical unit, being part of the promotional material related to said project. "galaxias!" is composed by the producer DECO*27, the DJ Teddyloid, and the voice actress and singer Kou Shibasaki, being the latter the one who come with the idea for galaco. Although it hasn't been stated, it's evident that galaco was designed to follow the same galactic concept used on galaxias!, as it's reflected on her attire design and name.
Following her name and concept, galaco has a strong reference to galaxies and cosmos, which reflected on the nebulae pattern on her clothes. Her design also seems to adopt some princess-like traits, particularly for her haircut and crown. Other characteristic traits are her multicolored hair locks and the triangular patterns on her design.
With the release of the NEO versions, galaco's appearance was redesigned to have a more delicate appearance, while keeping her iconic traits, like her "cosmic" vibe.