Holding his Gibson guitar tightly, Mafuyu Satou leaves his dark apartment to start another day of high school. While napping in a quiet spot on the gymnasium stairs, he meets fellow student Ritsuka Uenoyama, who scolds him for letting his guitar strings rust and break. Seeing Uenoyama's knowledge of the instrument, Satou begs him to repair it and teach him to play. Uenoyama eventually agrees and invites him to join a jam session with his two bandmates: bassist Haruki Nakayama and drummer Akihiko Kaji. Satou's voice is strikingly beautiful, filling Uenoyama with the determination to make him the band's lead singer. Though hesitant at first, Satou accepts the offer after an emotional meeting with an old friend. With the support of his new friends, Satou must not only learn to play guitar but also come to terms with the mysterious circumstances that led him to own it.