It was just another day. The sky split open. Literally, the sky cracked apart. And from within, beings and beasts from another world crossed over. Thus, the days of peace came to an end.

The world was filled with screams and weeping, and countless people died. The government sent the military, but even they were useless against the things that came through the Gate. People fell into despair and were ready to give up hope.

But there was hope. Perhaps due to the influence of the Gate, rare individuals who awakened special abilities appeared, and they resisted and fought back against the invaders.

Since the first Gate incident, the following groups have emerged: