Shirou’s mundane existence as a low-paid construction worker is upended when he encounters Lucy, a naked girl who has fallen from the sky. Drawn in by her peculiar and distinct personality, he brings her to meet his apartment mates. However, upon returning to the apartment after only a few minutes, Shirou discovers that Lucy has vanished, his friends have been massacred, and an ogre-like stranger stands amid the devastation. The large man abruptly drags Shirou out of the apartment building just moments before it explodes! Shirou is shoved down into the city’s sewage system and is rescued by a mysterious man...