In this world there exist spiritual pathways called Gates that draw in the souls of the departed and move them to a new realm of existence. however, at times, the Black Gate does not wait for death... but instead forcefully sucks out the souls from the living.

Senju is a "Mitedamashi", an agent with the power to summon or seal gates , and save people's souls. He is guardian to Hijiri, a boy he saved. After Hijiri discovers his own hidden powers, he begins a journey of self-discovery where the distant past comes back to haunt him and his choices determine life and death, not only for those he cares about, but the whole world!