"One and Only"

Although the group continues to grow in popularity, Muni is bothered about receiving no attention beyond her VJ title and wants to increase her presence by singing an image song. Unsure of how to compose the ideal song, Rei visits Muni's house for a sleepover, where they bond but Rei continues to struggle with writing. Although the song is disorganized, the group decides to proceed and invites Rei to join them onstage as a keyboardist. After their concert, the four formally change the unit name to "Happy Around!" as a reference to Rinku's catchphrase. To Muni's chagrin, her peers focus their praise on Rei instead.