A tale of ambition, power, and battling demons

Hellmet Rock is a boy who dreams of having a rock band. On his 15th birthday, he gets a magic electric guitar with a demon inside named Melvis. They strike a deal: in exchange for unmatched guitar skills, Hellmet owes Melvis a future favor. Soon after, Hellmet forms a successful band, but this fame draws the attention of other demons wanting his magical guitar, starting his perilous adventure.