Black Gate

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, a Black Gate appears, and the Black Gate does not wait for death...but instead forcefully sucks the souls out of living humans! 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 whose life he once 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!

(Source: TOKYOPOP).