There are currently that correspond to the first three seasons of the anime: Season 1 OVA: " I'm Harvesting Breasts! " (Episode 13) Release: September 6, 2012
While investigating a cursed coffin, Issei is possessed by a perverted Egyptian magician named Unas. To free him, the Gremory group must complete a bizarre quest involving a stray devil and "harvesting" energy. Season 2 OVA: " I'm Enveloped in Breasts! " (OVA 2) Release: March 15, 2015 High School DxD OVA
Because these OVAs were released as bonuses for light novels or Blu-ray sets, their numbering can be confusing. To keep the timeline straight, follow this order: There are currently that correspond to the first