"Eien/Universe/Believe in Love" (永遠/Universe feat. Crystal Kay&Verbal(M-Flo)/Believe in LOVE feat. BoA?) is BoA's twenty-seventh Japanese single. It was released on February 18, 2009 in two formats, CD-only and CD+DVD. The CD edition also comes in a first press limited edition. The second A-side, Universe, features fellow J-pop singer Crystal Kay and label mate, Verbal of M-Flo. The third A-side is the acoustic version of Ravex's single "Believe in Love", which features BoA. The 4th track on the Limited Edition version of the single, Best Hit Mega Blend [Limited Edition Bonus Track], is a mashup of multiple of her best hits in Japan.