100% Happiness

100% Happiness (100%ハピネス, 100% Hapinesu) is sung by Momo's voice actor, Soichiro Hoshi. The song lyrics were written by, and the song was composed and arranged by.

100% Happiness was originally released as part of the 12 SONGS GIFT project where all the idols from IDOLiSH7, TRIGGER, and Re:vale released solo songs on their birthdays. The song was released as a single on November 11, 2018, which can be purchased digitally on the iTunes Store, animelo mix, music.jp, mora, and Recochoku (レコチョク). It was also added to the game on November 11, 2018, and is available in normal lives after clearing Part 1 Chapter 1.6.