A mundane existence as a struggling construction worker is suddenly disrupted for Shirou when he stumbles upon a nude girl named Lucy, who has plummeted from the sky. Her distinct character intrigues him, leading him to introduce her to his apartment comrades.
However, upon returning to the dwelling after a short absence, Shirou discovers that Lucy has vanished, his companions have been ruthlessly eliminated, and an almost monstrous stranger stands amidst the havoc.
Without warning, the bulky individual wrenches Shirou out of danger moments before the entire complex erupts into flames. Forced into the bowels of the city's sewer system, Shirou is rescued by a cryptic figure...
