Is Bocchi the Rock! Movie: Hoshi no Ashiato hentai?
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

Movie · 1 episodes · PG-13 - Teens 13 or older
CGDCT, Comedy, Music
Prequel to Bocchi the Rock!, set prior to Kessoku Band's formation.
View on MyAnimeListShare
Check another title