The story begins when Heitor Villa-Lobos, a teen guitarist, is kicked out of his band as a result of his former bandmates' greed. On returning home, he accidentally falls into a hole that leads him to an underground world inhabited by mutants. Once there he meets Layla and her friends, Lud and Bob, who make up a rock band called "Under-Undergrounds". Heitor befriends the trio and joins the band, while at the same time seeking help to find his way back to the surface and his home.