is a Japanese band consisting of two female members, Yui Niitsu ("Yui") and Yukari Katoh ("Yuka").
* Harmonia (ハルモニア), 2nd ending theme song for Naruto (episodes 26-51)
* Hōkigumo (ホウキ雲), 1st opening theme song (episodes 1-29) and 7th ending theme song for Yakitate!! Japan (episode 69)
* Kokoro Biidama (ココロビーダマ), 6th ending theme song for Yakitate!! Japan (episodes 63-68)
* Utatane (ウタタネ) (June 23, 2004)
* Mugen Factory (夢現ファクトリー) (May 24, 2006)
*http://www.rythem.info/ Rythem's official website (in Japanese)
*http://www.sonymusic.co.jp/Music/Arch/AI/Rythem/ Sony's official page for Rythem (in Japanese)