IDOLiSH7 Vibrato S01 E08 Let's Do Summer! (2)

IDOLiSH7 arrives at Summer Island Music Festival. Riku bumps into Tenn at the hotel and suggests they perform the song "Let's Do SUMMER!” at the end of IDOLiSH7's performance. What's Gaku, Tenn and Ryuunosuke's final call?