Oji Tanaka has a wife, a child, and a mundane job as a salaryman in Tokyo's modern society. However, his life was not dull to begin with; fifteen years ago, he was known as "Gabriel," the leader of a short-lived heavy metal band called Black Heaven. Oji's life takes a sudden turn when a mysterious blonde woman named Layla invites him to pick up his Gibson Flying V and once again display his "legendary" guitar skills, unaware that his music generates power for a massive weapon in an intergalactic war.