As the sole survivor of a horrendous and rather mysterious accident, Mitsuko, a typical Japanese teenager, can safely say that her day has got off to a bad start. It seems that an unstoppable force of nature, a doomed field trip, and a strange case of amnesia can easily coexist in a bizarre parallel universe, where a desperate Mitsuko is always on the run from something inexplicable, intangible, and utterly deadly. However, that's not all. Amid piles of fresh dead bodies, mounds of scorching bullet shells, and rivulets of fragrant young blood, frail Mitsuko must fight to stay alive, before her already messed up day becomes even stranger. But, the question still remains. Who is the enemy?