Hell Teacher Nube OVA(1998)

Hell Teacher Nube OVA is a supernatural action series following an unconventional educator with demonic powers. Nube faces three escalating supernatural threats: a wall-dwelling demon, a restless young spirit seeking her lost harmonica, and Zekki, a formidable demon and brother to Baki—the creature that inhabits Nube himself. The OVA balances horror and action as Nube leverages his dark connection to combat increasingly dangerous supernatural forces. Each encounter tests both his combat abilities and his moral compass, blending dark fantasy elements with the tension of a teacher protecting those around him from otherworldly threats.