F9, also known as Kiyono (きよの), is an utaite whose voice is described to have a "crystal clear" quality to it, along with the ability to hit high notes and maintain control. She first debuted under the name Kiyono in the summer of 2007, and mostly sang covers of Sound Horizon songs. On March 31, 2008, she uploaded a cover of minato's Soar. The video quickly rose to the #1 spot in the music rankings (there was no "utattemita" category back then), and minato himself wrote a blog post detailing how he was overwhelmed with feeling by F9's voice.

Read more about F9 on Last.fm.