High School DxD OVA

A strange rumor spreads through Kuoh Academy: girls are vanishing and returning sick, with their breasts mysteriously reduced in size. Issei and the Occult Research Club investigate, expecting another supernatural threat, only to stumble into a bizarre case perfectly designed to capture Issei's attention.

Later, Issei and Asia accompany Rias to examine a supposedly cursed coffin. The object contains the spirit of an ancient Egyptian magician named Unas, who possesses Issei and proves almost as shameless as his host. Freeing Issei requires settling the curse that bound Unas after his own disastrous attempt to pursue a devil woman, turning a routine investigation into an unusually personal exorcism.