High School DxD Hero: Holiness Behind the Gym

ハイスクールD×D HERO 体育館裏のホーリー

Issei Hyoudou, the lecherous Kuoh Academy student killed on his first date and revived as a devil by the crimson-haired Rias Gremory, headlines this preview special tied to the Hero season. It recaps how Issei joined Rias's Occult Research Club and fought alongside her peerage, including the gentle Asia Argento, then closes on a quieter sports-festival scene behind the school gymnasium. The special is supplementary, released ahead of the fourth season rather than as a standalone entry point.