Sound of the Sky OVA
So Ra No Wo To OVA · ソ・ラ・ノ・ヲ・ト
Synopsis
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.
Studios: A-1 Pictures, Aniplex
Source: ORIGINAL