Paradistar(2003)

Paradistar

While being chased by the Yakuza for his family’s debt, Chiba Tamao runs into a man who wants to “eat him”, named Kurotengu. Kurotengu ends up saving Chiba’s life, and in the process it’s revealed that Kuro is actually a mo no noke *type of Japanese demon* called a Tengu. Now a “friend” of Kuro’s has paid of Tamao’s debt to the Yakuza, but to pay him back, Tamao needs to work with Kuro in a boy band, while at the same time risking himself to be “eaten” by mo no noke.

(Source: Anime News Network)