Kachou Ouji Gaiden  

Legend of Black Heaven, 課長王子 外伝

Ouji Tanaka was a typical mid-level executive in his job as a section chief. Despite this, he had a history as a rock musician. One day, an alien named Layla appeared before him and requested his assistance in battling a hostile alien species. She asked him what weapon he would use. His answer was his powerful rock spirit!