"It's a promise. We will fly together, until the farthest end of the sky".
In a drifting world, where islands are floating above mists and where monsters are swimming inside those mystic mists unfolds the story of Will, an "Armed Postman" whose job is to deliver peoples desires and emotions contained in an "Envelope", and Jessica, a mysterious girl.
Will is bad at reading the winds while Jessica is afraid of flying due to a trauma in the past. These two people who cannot complement each other and cannot fly have the same dream which others wouldn't think of: to challenge the mist of death and find out what is at the farthest end of the sky. A refreshing fantasy adventure of a two-seated "Winged Ship", flying above the clouds.