[6] The limited edition of the regular edition comes with the song "Hoi Hoi", released by the sub-unit Rainbow Pixie, which is composed by the members SeungAh, Jisook and HyunYoung.

was produced by Han Sang Won, same producer of the song "Not Your Girl", included as a B-side on the single "Mach", as well the Korean version, included on their debut EP Gossip Girl.

on February 24 and later revealed on YouTube by their Japanese label, Universal Sigma, on the same day.

[9] The preview was revealed along with the announcement of their debut Japanese album Over the Rainbow.

[11] The group is scheduled to make another performance of the song on NTV's show Happy Music on April 6.