From The Black Abyss:
Spirits known as kamui are thrown into chaos when the sacred spirit Okikurumi is taken from Atsuma's village, and the imbalance threatens to destroy Earth. Infused with the spirit of an ancient sword, Atsuma must leave his village to reclaim Okikurumi.

He encounters NOA, an organization of youths who wield the power of the kamui, and who may hold the key to Okikurumi. Atsuma is recruited into NOA by Sumire, a young woman with an empty soul who yearns for a miracle. Atsuma and his new companions must work together to find Okikurumi before the world is destroyed.