Mugen Kigen (夢幻期限 / Fantasy Era) is the ninth single by Japanese soloist misono.

For this single, misono worked with Onsoku Line (Japanese: 音速ライン / English: onoso9line) and their vocalist and guitarist Yoshiyuki Fujii.

As with both Zasetsu Chiten and Juunin Toiro, Mugen Kigen charted for two consecutive weeks.

[3][4] The CD contained the title track, the b-side "Last Song" and instrumental for "Mugen Kigen."

The song was performed by Onsoku Line and Tanahashi "UNA" Nobuhito from the soft rock band Every Little Thing.