According to the official website, two extra episodes will be included in the Blu-ray and DVD volumes 4 and 7 of "Sora no Woto". The volumes 4 and 7 will be released on June 23rd (episode 7.5) and September 22nd (episode 13), respectively.
Genres: Music, Sci-Fi, Slice of Life
Watch Sound of the Sky OVA episode 1 online — subbed and dubbed, with automatic AniList / MyAnimeList progress sync.
Primarily Female Cast · Military · Female Protagonist · Cute Girls Doing Cute Things · Ensemble Cast · Post-Apocalyptic · Lost Civilization · Episodic · Kuudere