On the day of the "Meisei Music Festival". Yuki begins to play the intro of "POWDER SNOW" instead of "Koiiro Sora", the repertoire prepared. The backing band starts playing accordingly. And another singing voice overlaps from the middle---It was Rina who regained her voice. Talking with Akira in her Echoes, Touya regains her sealed memories. When I was young, my memory of a certain summer was——.