"Diamond Only" is the eighth single released by E-girls. It was released in 4 editions: CD+DVD, CD Only, One Coin CD and MUSIC CARD editions, one per member. The song was used as theme song for the drama Koibumi Biyori, which 10 members of the group starred on it, and for Samantha Vega ♡ Honey Bunch -Disney New Collection- CM. The One Coin CD and MUSIC CARD editions were only sold at mu-mo online store and at LDH Mobile store. The title song was released digitally on February 12, two weeks prior to the physical release, as their seventh digital single.
