Hibiki no Sora

 is the sixth single by Yoshioka Aika. It was released on February 23, 2011, and peaked at #67 on the Oricon singles chart.

Single Information
Hibiki no Sora w uassed as the opening theme for the game Hakuouki: Zuisouroku DS, while Hajimari no Uta was used as its ending theme.
 * Lyrics: Isogai Yoshie (Track 1), Uezono Ayune (Track 2)
 * Composition: Ono Takamitsu (Track 1), Ueno Yoshio (Track 2)
 * Arrangement: Toda Akiyo (Track 1), Anze Hijiri (Track 2)

Tracklist

 * 1) Hibiki no Sora (響ノ空)
 * 2) Hajimari no Uta (はじまりの詩)
 * 3) Hibiki no Sora (響ノ空) (Instrumental)
 * 4) Hajimari no Uta (はじまりの詩) (Instrumental)