Is Drifters (OVA): Kokuou-sama Goranshin hentai?
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

Special · 2017 · 1 episodes · PG-13 - Teens 13 or older
Adult Cast, Comedy, Parody, Seinen
Final episode of Kokuou-sama Goranshin released with the new Drifters episodes 13-14 Blu-ray disc.
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