The story is set in a world where artificially intelligent, emotional androids called Phiroids were developed before a rapid decline in human civilization.
An emotionless young man named Rei with a mechanical right hand is cared for by a girl in a small town as he gradually learns how to express emotions.
The music on the soundtrack was composed and arranged by Shinji Orito, Ryō Mizutsuki, Tomohiro Takeshita, Yūichirō Tsukagoshi and Meeon.
The album contains one disc with 17 music tracks composed, arranged and produced by Shinji Orito, Ryō Mizutsuki, Tomohiro Takeshita, Yūichirō Tsukagoshi and Meeon.
"Todoketai Melody / Towa no Hoshi e" (届けたいメロディ/永遠の星へ) is a single from the visual novel Harmonia containing the game's theme songs sung by Ayaka Kitazawa and Haruka Shimotsuki.