MEIKO是山叶以Vocaloid语音合成引擎为基础开发，Crypton Future Media贩售的虚拟女性歌手软件第一作；或此软件的印象角色（这只是软件的象征，不会在实际使用时出现）。于2004年11月发售，开放价格，官方估计系列软件实际价格约19,950日圆。由拜乡芽衣子（拝郷メイコ）提供原声，软件名称也是取自拜乡芽衣子的名称芽衣子（メイコ）。日语第一套VOCALOID的产品，擅长流行曲、摇滚乐、爵士乐、R&B、童谣等广范围歌种。VOCALOID 3引擎声库KAITO V3是由Crypton Future Media开发并贩售，于2014年2月4日发售。

MEIKO is a humanoid persona voiced by a singing synthesizer application called Vocaloid developed by Yamaha Corporation. Her voice is sampled by Meiko Haigō. She has performed at live concerts onstage as an animated projection along with Crypton Future Media's other Vocaloids (like Hatsune Miku). She was the fourth Vocaloid ever released and the first to sing in Japanese.