ZYX (ジックス, Jikkusu, pronounced zicks) was a short-lived Japanese pop group made up of five Hello! Project Kids members led by Mari Yaguchi of Morning Musume. Yaguchi acted as a mentor and the group released two singles. ZYX is important in that it is the first unit that Hello! Project Kids officially joined with the second being Aa! formed in 2003, the third being Berryz Kobo in 2004, and the fourth being Cute in 2005. As Saki Shimizu and Momoko Tsugunaga were selected to become members of Berryz Kobo in 2004, the activity of ZYX virtually ended.
The name ZYX is a kind of acronym using a somewhat intricate play in notation. "Z" and "Y" are taken from the phrase Zettai Yume o Bai ni (絶対、夢を倍に, Definitely double your dreams) "Bai ni", meaning "double in size", is represented not as "B" but as a multiplication sign "×" which was then represented by the letter "X". Also, the letters ZYX are the last letters of the English alphabet in reverse order. In Hello! Project, this inverted order naming is followed by the groups "W" created in 2004, "v-u-den" in 2005, "The Possible" in 2006, and SI☆NA in 2008. This line-up of groups continues the reverse alphabetical naming (ZYX-W-VU-T-S).
In 2009, the unit was revived as ZYX-α (ZYX Alpha). Of all the original members, only Momoko Tsugunaga remains (Mari Yaguchi, Megumi Murakami and Erika Umeda are no longer a part of Hello! Project and Saki Shimizu and Maimi Yajima are a part of High-King).
Mari Yaguchi (Leader),
Risa Niigaki (Leader) (left May 2012),
Koharu Kusumi (left December 2009),
Saki Ogawa (left August 2011)