Fraw and Kio are angels, and it's their duty to protect the passage of souls to Heaven. When the two were growing up, Kio always looked after Fraw. However, their roles are suddenly reversed when Fraw is promoted to one of the highest ranking classes of angel, and Fraw takes it upon himself to protect Kio.

Can Fraw keep his new position a secret while he and Kio battle against the Manifis, evil spirits that feed on humanity? And what is so unusual about Kio and his wings...? (Source: Storm in Heaven/Bamboo Feathers)

Volume 1 starts off with chapter 0, originally a one-shot called "Eden".