Happy Around! reaches eighth place in the Sunset Stage rankings to qualify for the competition, but their position is jeopardized by the rise of Photon Maiden. After Photon Maiden's latest performance, the two groups are tied for the rank and are subject to a one-on-one "Battle Mix Party" to break the tie. Needing an especially impressive song to give them a boost, Rei composes a series of melodies, though her preferred piece is shelved as the others feel it does not fit their image. While they proceed with a song that Rinku is comfortable with singing, Rei continues to mull over her favored melody before figuring that she could sing it herself.