IDOLiSH7 - Season 3 Episode 9 Re:vale
Overview: Moved by Re:vale's concert, Momo writes a fan letter describing how "Our Incomplete Selves" made him feel. Banri and Yuki are touched by the letter, which encourages them to continue making music. Five years after the formation of their band, they're approached by a man named Kujo who offers to help them debut.