Three years after his musical partner Kai Amano died in a traffic accident just before their major debut, Kyōsuke Tsurumaki has quit music and lives as a freeter, having lost all motivation. His life changes unexpectedly when Kai suddenly appears at his home, acting as energetic and outspoken as he was before his death. Kai confronts Kyōsuke with the belief that doing nothing while alive is no different from being dead, and persuades his former partner to return to the world of music. As Kyōsuke rediscovers the joy of creating sound together, he is forced to confront the fact that his time with Kai may not last forever.

The story is set in contemporary Japan and follows Kyōsuke Tsurumaki, a 22-year-old who formed the music duo Kanitama with Kai Amano during high school. After Kai’s death, Kyōsuke abandoned his musical ambitions and became disillusioned. Kai Amano is Kyōsuke’s deceased partner and a talented guitarist and lyricist, whose sudden reappearance drives Kyōsuke to face music again. Other characters include Takeshi, Makoto, and Minoru.

The manga is based on the original light novel series and follows its storyline, beginning with the premise of loss and an unexpected supernatural reunion. The narrative focuses on Kyōsuke’s emotional journey from grief and stagnation to rediscovering his passion for music, guided by the memory or presence of Kai. The central conflict revolves around whether Kyōsuke can overcome his past trauma and whether his renewed partnership with Kai can endure, as their time together carries an inherent tragedy.