Breath of Copernicus [Copernicus no Kokyuu] (Complete, Scanlated)

The story happens in a circus in Paris in the 1970's. Much is made of the romance of the circus atmosphere, of flying through the air on a trapeze, etc. Think cirque here, not circus. The tawdriness comes from the circus master pimping out his performers to anyone willing to pay. And there's decadence - ghosts who wander into the action looking like teenaged girls even if they're the hero's brother, and abandoned neurotic women with a thing for inflicting pain, and possible murder and unspoken pining and a hero who looks about to perish at any moment from terminal angst.