High school student Nabi is saved in a near-death experience by a mysterious, beautiful man. Turns out, only she saw him. Ever since that day, Nabi begins seeing dark, ominous beings called 'Reapers', parasite-like creatures that feed on negative energy. With the help of the mysterious man, Nabi is introduced to a world she never knew existed. Will Nabi be able to hone her abilities and survive in this world?