Jigoku Sensei Nube OVA

Nube’s classroom is never far from the supernatural. A confrontation with Kabeo, a wall-dwelling yokai, forces the teacher to rely on the Youjin technique when brute force alone is not enough.

A more insidious threat follows when the mysterious Bukimi-chan begins appearing in children’s dreams, drawing them into a maze from which a wrong turn can mean never waking up. When Hiro is caught inside, Nube enters the nightmare to pull him back.

Then Zekki descends from hell to free his older brother Baki, the demon sealed within Nube’s left hand. Zekki’s overwhelming spiritual power leaves even Nube outmatched, forcing Tamamo, Yukime, and their allies into a desperate stand against an enemy who could tear apart everyone Nube is trying to protect.