"Mugen Kigen (夢幻期限, Fantasy Era^?)'" is Misono's ninth solo single, and is the third of a quadrilogy of rock-themed songs. It was released on January 30, 2008. The b-side track, "Last Song" was later featured on Misono's second album, Sei: Say with an extended ending.

Tracklisting [link]

CD [link]

1. Mugen Kigen (夢幻期限, Fantasy Era^?)
2. Last Song (ラストソング^?)
3. Mugen Kigen (Instrumental) (夢幻期限, Fantasy Era^?)

DVD [link]

1. Mugen Kigen (Video Clip) (夢幻期限, Fantasy Era^?)
2. Misono Video Comment (misonoコメント映像^?)
3. Mugen Kigen: TV Spot 15 Seconds + 30 Seconds (夢幻期限-TV SPOT 15秒+30秒-, Fantasy Era^?)