Kamui

KAMUI (カムイ) is a shōjo manga series by Japanese author Shingo Nanami. The manga was serialized in the Monthly Stencil magazine, and later serialized in Monthly Gangan WING magazine, and published in Japan by SQUARE ENIX.

Plot
In post-apocalyptic Japan, a devastating earthquake called the "Great Sinker" sank 1/3 of the southern islands and cities were destroyed. Monsters known as Atanan appear, creating chaos and fear among the survivors. Youths with supernatural powers fight against the Atanan and control the government-less ruins.

Fearing that the imbalance of the spirits known as the kamui will destroy the Earth, a teenager named Atsuma is sent from his village to retrieve Okikurumi, the sacred kamui, to restore the balance and peace. He joins NOA, the organization of youths with supernatural powers, to find Okikurumi and to stop the world destruction.