年幼的空深彼方曾在废墟里遇到过一个女性，这个女性手拿着一个小号为彼方吹奏了一曲《奇异恩典》（Amazing grace）。因此彼方对成为喇叭手有了兴趣，带着“进了军队就能吹小号”的错误想法，空深彼方加入了军队，并驻留在赛兹（セーズ）的第1121小队。故事从她被卷入泼水节的骚动开始。故事时间是在不太遥远的未来，过于漫长的战争的痕迹污染了整个大地，于是，世界迎来了静静衰退的季节。假名、汉文等都是远古象形文字，连人口也很少，科技也退化没有再进步下去。
空之音 (季节 0)
Drinking Party: Fortress Battle (Episode 7.5) 0.0
播出日期: 2010-06-23
运行时间: 24 min
概述: Rio, Filicia and Kureha have trouble keeping their illegal alcohol distillery a secret from both Kanata and Yumina. After giving everyone a special brew of tea, spiked with their home-made alcohol, Filicia suggests a mock battle using water guns that, if Kanata’s team wins, she would be told the truth. Having gotten a little drunk from the alcohol, everyone gets a bit too into character. Kanata’s team gets the upper hand when Noël brings out a Gatling gun, taking down Filicia in the process. However, they soon run out of ammo and Noël and Yumina get knocked out. Kanata eventually stumbles upon the secret distillery and comes up against Rio and defeats her. After recovering from the battle, Kanata promises to keep the distillery a secret, before spending the night with everyone getting drunk. Kureha, being the only one who could not get drunk, is left to recall the horrors the others subjected her to.
The Sound of the Sky: The Horizon of Dreams (Episode 13) 0.0
播出日期: 2010-09-22
运行时间: 24 min
概述: When asked by Mishio what her dream is, Kanata is unsure how to answer. Kanata is given a letter sent to Rio from the Roman Emperor, and goes to find Rio so she can sign it. Whilst in town, she runs into Yumina and learns why Mishio asked her. Kanata later learns from Naomi and Maria that Rio might have wondered off somewhere. Kanata later finds Rio at some ruins, who was wondering about the true story behind the Maidens of Fire that Aisha had told them. Rio then explains that outside of Seize, there are a lot of wars going on. Later that night, Rio takes Kanata on a hot air balloon ride, where she tells her her dream of rebuilding the airplane. The next day, as Kanata is picked to play the role of a fire maiden, Kanata decides her dream is to follow Rio on her dream.
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集 12
集 2