MY ANIMA BOY

In the military state of Melkid Defensive Nation, which has been waging war with monsters for centuries, the court orchestra "Screw Heads", although a symphonic band, is ordered to create a 'pop song with love as its theme'.
The protagonist and composer, Paolo, struggles with the unfamiliar task of writing lyrics, when suddenly, the beautiful young member Tiyakins becomes inexplicably angry...

A short BL novel that weaves elements of war and sexuality into a commoner's story of creating their first pop song.

[From Steam]