Is Aria the Crepuscolo hentai?
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

Movie · 2021 · 1 episodes · PG-13 - Teens 13 or older
Iyashikei, Sci-Fi, Shounen, Slice of Life
Aspiring Orange Company Undine Anya Dostoyevskaya feels dejected upon learning that her gondolier mentor, Alice Carroll, is not spending much time with her own mentor, Athena Glory. Athena—the Undine-turned-opera singer—has been attempting to arrange a meeting with Alice, but the latter seems to be avoiding her for unknown reasons. To try and resolve this predicament, Anya calls upon her fellow Undines Ai Aino and Azusa B. McLaren. As the trio works to bring Alice and Athena together, Anya gains a deeper insight into her seniors' feelings, which might just be the key to untangling the uncertainties between them. [Written by MAL Rewrite]
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