This list is, and will always be, incomplete. Please feel free to contribute by adding utaites, their romaji and hiragana name, what sort of singer they are and their gender.

96neko/96猫 - Female (Ryouseirui)
Che:Sakurai/che:櫻井 -Female (Ryouseirui)
Choucho/ちょうちょ - Female (Professional)
clear    /クリア - Male
Cocolu/ココル - Female (Ryouseirui)
Dasoku/蛇足 - Male
Gero/げろ - Male
Glutamine/ぐるたみん - Male
Hanatan/花たん - Female
Hitori/ひと里 - Female (Ryouseirui)
Jenga/ジェンガ - Male (Ryouseirui)
Kogeinu/コゲ犬     -...